Journal of the Institute of Petroleum, Vol. 28, No. 220

Vo l. 2 8 . N o . 2 2 0 . Ap r i l 1 9 4 2 .

B y R . L . Br o o k s

(C o n s e r v a to r o f F o re s ts , T r i n id a d ) .

I

.

D

S u c h a la rg e c o n s u m p tio n o f lo c a l w o o d , w h ic h is n e a r ly d o u b le t h a t o f n o r m a l y e a rs , c o n s titu te s a c o n s id e ra b le d r a in o n a v a ila b le s u p p lie s , e s p e c ia lly o f th e m o re p o p u la r species. T h e e v e n la r g e r c o n s u m p tio n o f im p o r te d w o o d re p re s e n ts a c o n s id e ra b le e x p e n d it u r e o f d o lla r c u r re n c y a n d th e use o f a c o n s id e ra b le a m o u n t o f s h ip p in g . B y n o m e a n s a l l o f th is c o n s u m p tio n is re p re s e n te d b y n e w w o rk s : a la rg e p o r t io n o f i t goes t o re p la c e m e n ts a n d re p a irs , a lth o u g h fig u re s o f t h e r e la t iv e p ro p o r tio n s a re n o t a v a ila b le .

N o one c a n foresee h o w lo n g t h e p re s e n t crisis w i l l la s t, n o r w h e t h e r th r o u g h o u t t h e crisis th e r e w i l l b e a v a ila b le a m p le su p p lie s o f t i m b e r f r o m t h e U . S . A . a n d C a n a d a a n d ships i n w h ic h t o c a r r y t h e m . I t is o u r b o u n d e n d u t y , th e re fo r e , t o a v o id w a s te o f t i m b e r f r o m w h a t e v e r s o u rce, a n d w e c a n d o t b ia o n ly b y t h e a d o p tio n o f a p p r o p r ia te m e a s u re s , a t p re s e n t a lm o s t n o n -e x is te n t in t h e C o lo n y , t o p ro lo n g to t h e u tm o s t t h e lif e o f a l l t h e t i m b e r t h a t w e use, a n d t o e n a b le t h e use in one f o r m o r a n o t h e r o f species o f t i m b e r w h ic h w e h a v e d esp ised i n t h e p a s t a n d a llo w e d t o r o t u n u s e d o n t h e g r o u n d .

T h e d e c a y a n d d e s tru c tio n o f t im b e r c a n , e v e n i n t h e tro p ic s , b e v e r y c o n s id e ra b ly r e t a r d e d b y t h e a d o p tio n o f c e r ta in p r a c tic a l c o n s tr u c tio n a l m e th o d s a n d b y t h e use, w h e re in d ic a te d , o f t im b e r t r e a t e d w i t h p re s e r­

v a tiv e s . T h e f o r m e r m easu res in v o lv e l i t t l e , i f a n y , in c re a s e i n e x p e n d i t u r e ; t h e l a t t e r m u s t in e v i t a b l y in c r e a s e t h e fir s t cost o f t h e t im b e r , b u t i f i n t e llig e n t m e th o d s a re u se d a c c o rd in g t o t h e r e la t iv e d a n g e rs t o w h ic h tim b e r s o f v a rio u s ty p e s a re t o b e e x p o s e d , t h e in c re a s e d cost is m o re t h a n o ffs e t b y t h e in c re a s e d life o f t h e t im b e r .

B e fo re c o n s id e rin g re m e d ia l m e a s u re s , h o w e v e r, i t is o f t h e u tm o s t im p o r ta n c e t o h a v e a b a s ic k n o w le d g e o f th e k in d s a n d h a b its o f t h e p es ts w h ic h cause d e c a y a n d d e s tru c tio n in t im b e r , since r e m e d ia l m e a s u re s ig n o r a n t ly a n d u n in t e llig e n t ly a p p lie d cause w a s te o f m o n e y a n d o fte n c o m p le te fa ilu r e . T h e e n e m ie s o f t im b e r o n la n d a re f u n g i a n d in s e c ts , ai in t h e sea m a r in e b o rers .

Fu n g i.

F u n g i re p re s e n t a lo w f o r m o f p la n t life , w h ic h does n o t possess t h e c o lo u r in g -m a tte r (c h lo r o p h y ll) b y w h ic h o th e r p la n ts , w i t h th e h e lp o f lig h t , a re a b le t o b u ild u p t h e g re a te r p a r t o f t h e i r fo o d m a t e r ia ls f r o m

* Received 26th February, 1942. Paper presented to the Trinidad Branch, 26th November, 1941.

T H E P R E S E R V A T I O N O F T I M B E R , *

th e c a rb o n d io x id e in th e a i r ; c o n s e q u e n tly fu n g i a re fo rc e d to o b t a in t h e ir o rg a n ic fo o d f r o m s u p p lie s i n d e a d o r liv in g p la n ts a n d a n im a ls .

T h e m a in b o d y o f th e fu n g u s , k n o w n as t h e m y c e liu m , is b u i l t u p o t a m ass o f fin e th re a d s o r hyphse : th e s e hyp hse, i n t h e case o f w o o d -d e s tro y in g fu n g i, p e r m e a te th e w o o d cells a n d a re a b le t o d ig e s t th e w o o d substances, w h ic h a re m a in ly c o m po sed o f m a t e r ia l e a s ily c o n v e rte d t o s u g a r.

T h e f r u i t i n g b o d y o f t h e fu n g u s , w h ic h is in m o s t cases t h e conspicuous p a r t , is u s u a lly f o r m e d o n ly a f t e r a la rg e a m o u n t o f m y c e liu m h as been fo r m e d . T h e s e f r u it in g b o d ie s , w h ic h a re f o r m e d in t h e o p e n , p ro d u ce e n o rm o u s n u m b e rs o f m ic ro s c o p ic spores : i t has b e e n e s tim a te d t h a t th e f r u i t i n g b o d y o f a d r y - r o t fu n g u s a fo o t s q u a re c a n t h r o w o ff som e 5 m illio n spores p e r m in u t e f o r a p e r io d o f s e v e ra l d a y s . T h e s e spores, o f course, f u n c tio n as seeds, a n d as a re s u lt o f t h e ir im m e n s e n u m b e rs i t is c le a rly im p o s s ib le f o r a n y p ie c e o f w o o d in t h e o p e n n o t t o co m e in t o c o n ta c t w ith spores s o o n e r o r la te r .

F o r t u n a t e ly , h o w e v e r, f o r t i m b e r g e n e ra lly f u n g i re q u ir e c e rta in con­

d itio n s f o r t h e i r g r o w t h : th e s e a re as fo llo w s :—

( a ) S u i t a b l e F o o d M a t e r i a l .— N o t a ll t im b e r s p r o v id e a s u ita b le food m a t e r i a l f o r f u n g i : f o r e x a m p le , such w e ll-k n o w n lo c a l w oo ds as b a l a t a a n d p o u i p r o v e re s is ta n t t o f u n g i. A g a in , th e h e a r t-w o o d o f a ll species o f t i m b e r p ro v id e s a less s u ita b le fo o d m a t e r ia l t h a n th e s a p w o o d , a n d is c o n s e q u e n tly m o re re s is ta n t. C e r t a in fu n g i a re so h ig h ly s p e c ia liz e d t h a t t h e y w i l l a t t a c k o n ly o ne species o f w o o d ; o th e r d e s t r u c tiv e f u n g i a re u n a b le t o a t t a c k a b s o lu te ly s o u n d w o o d , b u t w ill r e a d i l y a t t a c k w o o d a lr e a d y in fe c te d b y som e o th e r fu n g u s .

(b ) A d e q u a t e S u p p l y o f A i r .— F u n g i re q u ir e o x y g e n f o r t h e i r re s p ira ­ t io n , a n d a re u n a b le t o g r o w in t h e a bsen ce o f a i r : t h a t is w h y tim b e r w h ic h is p e r m a n e n t ly s u b m e rg e d u n d e r w a t e r c a n n o t b e a tta c k e d b y f u n g i.

(c) A d e q u a t e S u p p l y o f M o i s t u r e .— F u n g i r e q u ir e m o is tu re fo r th e ir g r o w t h , a n d g ro w m o s t v ig o ro u s ly u n d e r v e r y d a m p c o n d itio n s . I t is a m o s t h e a r te n in g f a c t t h a t f u n g i c a n n o t g ro w i n t i m b e r w h ic h con­

t a in s less t h a n 2 0 p e r c e n t, m o is tu r e , b a s e d o n its o v e n -d r y w e ig h t.

T h is is a m o s t im p o r t a n t f a c t t o r e m e m b e r in c o n n e c tio n w it h th e use o f t i m b e r i n b u ild in g s .

( d ) S a t i s f a c t o r y T e m p e r a t u r e .— T h e o p t im u m t e m p e r a tu r e f o r fu n g i is a b o u t 8 0 - 9 0 ° F . : h ig h t e m p e r a tu r e s a re le t h a l t o fu n g i, w h ils t g r o w th sto p s e n t ir e ly a t lo w t e ih p e r a tu r e s a l i t t l e a b o v e fre e z in g p o in t.

E s p e c ia lly id e a l c o n d itio n s f o r th e d e v e lo p m e n t o f w o o d -d e s tro y in g fu n g i, in th e sha p e o f a n a b u n d a n t s u p p ly o f m o is tu r e a n d s ta g n a n t a ir , are p re s e n t in t h e case o f w o o d in c o n ta c t w i t h th e g ro u n d . S im ila r ly , cracks d e v e lo p in g in w o o d in t h e o p e n c o lle c t a n d h a r b o u r m o is tu re a n d fo r m a s a tis fa c to ry s t a r t in g - p o in t o f a t t a c k b y fu n g i.

I

.

T e r m it e s a re th e insects m o s t d e s tr u c tiv e t o t im b e r in T r i n i d a d a lth o u g h t h e n a t t a c k , a re n o t so severe as in m a n y o th e r c o u n trie s , a n d f t i y a w S 6 4 BRO OKS : TH E P R E SE R V A T IO N OF T IM B E R .

B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R . 6 5

res p o n s ib le f o r so m u c h d a m a g e to t im b e r in c o n ta c t w i t h th e g r o u n d as a re fu n g i.

T e r m ite s , c o m m o n ly c a lle d w h it e a n ts o r, lo c a lly , w o o d -lic e , a re so c ia l in sects liv in g in colo nies a n d d iv id in g t h e ir w o r k a m o n g s p e c ia liz e d castes : ea c h c o lo n y liv e s s h u t o ff f r o m th e o u ts id e w o r ld a n d w i t h n o in te r c o n n e c tio n w it h o th e r colo nies. T h e y fe e d o n cellu lo s e m a t e r ia ls a n d a t t a c k m a n y o th e r k in d s o f m a t e r i a l ; t h e ir in te s tin e s c o n ta in la rg e n u m b e rs o f P r o to z o a , w h ic h p re s u m a b ly a id in d ig e s tin g t h e fo o d , a n d w it h o u t w h ic h t h e t e r m it e c a n n o t liv e . A n i m p o r t a n t h a b it w i t h re fe re n c e t o t h e ir c o n tro l is t h e c o n s ta n t lic k in g o f t h e ir o w n b o d ies a n d o f th e b od ies o f o th e r m e m b e rs o f th e c o m m u n ity .

W o o d -d e s tr o y in g te r m it e s i n T r i n i d a d m a y b e d iv id e d in t o t w o m a in classes : d r y -w o o d t e r m ite s a n d s u b te r ra n e a n te r m ite s .

(1 ) D r y - wo o d T e r m i t e s .— T h e s e a re fc o n fin e d e n t ir e ly t o w o o d , liv in g in d r y , s o u n d w o o d o f tre e s , poles, p o s ts, b u ild in g s , f u r n it u r e , e tc . ; t h e y d o n o t e n te r t h e g ro u n d , a n d th e c o m m o n species r e q u ir e n o w a te r s u p p ly . T h e r e a re o n ly t w o fo rm s — s old iers a n d re p ro d u c tiv e s ; th e l a t t e r p e r io d ic a lly d e v e lo p w in g s a n d e m e rg e i n t o t h e o p e n . T h e s e a la te s (lo c a lly k n o w n as ra in -flie s ) f in d th e m s e lv e s m a te s a n d , a f t e r d ro p p in g t h e i r w in g s , e a t t h e ir w a y in t o som e p ie c e o f w o o d , p lu g g in g u p t h e i r e n tra n c e h o le a f t e r th e m , a n d fo u n d a n e w c o lo n y . D r y - w o o d t e r m ite s a t t a c k th e w o o d w o rk o f b u ild in g s a n d f u r n it u r e : t h e ir p res e n c e c a n be d e te c te d b y th e e x tr u d e d s m a ll fæ c a l p e lle ts , o f u n if o r m size a n d s h a p e a n d a b o u t t h e size o f p in s ’ h ea d s . T h e c o m m o n e s t a n d m o s t d e s tru c tiv e species in T r i n i d a d is C r y p t o t e r m e s b r e v i s .

(2 ) S u b t e r r a n e a n T e r m i t e s .— T h e s e te r m it e s liv e p a r t l y o r a lm o s t e n t ir e ly in th e g ro u n d , a n d i t is e s s e n tia l f o r t h e m a lw a y s to m a i n t a i n a c o n n e c tio n w i t h t h e g ro u n d , as i t is f r o m th is sou rce t h a t t h e y d e r iv e t h e ir m o is tu re . A l l t e r m ite s w o r k in g i n a s tr u c tu r e a b o v e g ro u n d w i l l d ie i f t h e ir c o n n e c tio n w i t h th e g r o u n d is p e r m a n e n t ly se v ere d . T h e y a t t a c k w o o d in o r o n t h e g ro u n d , o r b u ild c o v e re d r u n ­ w a y s to re a c h w o o d a b o v e t h e g ro u n d ; th e s e ru n w a y s a re c o m p o s e d o f p a rtic le s o f e a r t h a n d p a r t l y d ig e s te d w o o d , a n d f o r m t h e e s s e n tia l fin k w i t h th e s oil. S u b te rr a n e a n t e r m ite s h a v e th r e e fo r m s — r e p r o ­ d u c tiv e s , sold iers, a n d w o r k e r s ; th e r e p ro d u c tiv e s d e v e lo p w in g s , as i n th e case o f th e d r y -w o o d te r m it e s , m a t e , a n d fo u n d neAÿ colo nies.

S u b te rr a n e a n te r m ite s n e v e r p ro d u c e th e fæ c a l p e lle ts c h a r a c te ris tic o f th e d r y -w o o d t e r m ite s : t h e ir w o r k c a n be re c o g n iz e d b y t h e p re s e n c e o f a “ fra s s ” c o m po sed o f e a r th p a r tic le s , w o o d fra g m e n ts , d e b ris , e tc ., c e m e n te d to g e th e r b y s a liv a a n d faecal d e p o s its , w h ic h is u se d t o p lu g u p u n u s e d g a lle rie s o r o p e n in g s . E x t e r n a l a t t a c k c a n a ls o , o f course, be re c o g n iz e d b y th e C h a ra c te ris tic tu b e s . T h e t w o c o m m o n e s t g e n e ra o f s u b te r ra n e a n t e r m ite s a re H e t e r o t e r m e s a n d C o p t o t e r m e s , o f w h ic h th e f o r m e r is b y f a r th e m o s t d e s tru c tiv e to houses.

2 . P o w d e r - P o s t B e e t l e s ( L y c t i d c e ) .

T h e larvae o f t h e p o w d e r -p o s t b e e tle s d o a c o n s id e ra b le a m o u n t o f d a m a g e t o t im b e r in houses a n d f u r n it u r e . T h e a d u l t b e e tle is s m a ll,

F 2

66

a b o u t Tk in c h in l e n g t h ; i t la y s its eggs in th e w o o d , a n d th e b u r ro w in g larvae a re c a p a b le o f re d u c in g th e w o o d to a fin e p o w d e r. I he e x tr u s io n o f t h is fin e p o w d e r— q u ite d is tin c tiv e f r o m th e p e lle ts o f t h e d ry -w o o d t e r m it e o r th e “ frass ” o f th e s u b te r ra n e a n t e r m it e — in d ic a te s t h e presence o f a t t a c k . S a p w o o d is f a r m o re s u s c e p tib le t o a t t a c k t h a t h e a r tw o o d .

3 . O t h e r I n s e c t s .

T h e r e a re o th e r in s e c ts, such as th e B o s try c h id a e (a n o th e r f o r m o f p o w d e r- p o s t b e e tle ) a n d C e ra m b y c id s e o r L o n g h o rn s , w h ic h a re re s p o n s ib le f o r th e d e s tru c tio n o f t im b e r , m a in ly s a p w o o d , b u t th e s e a re o f r e la t iv e ly m in o r im p o r ta n c e , a n d p r e v e n t iv e m e a s u re s a re th e sa m e as th o s e f o r d ry -w o o d te r m ite s .

P

M

.

F r o m t h e fo re g o in g v e r y b r i e f o u tlin e o f t h e ty p e s a n d h a b its o f th e p r in c ip a l a g e n ts o f d e s tr u c tio n a n d d e c a y o f t im b e r , i t is c le a r t h a t th e ir v a r y in g h a b its a n d m o d e o f life m e a n th e a d o p tio n o f a v a r i e t y o f c o m m o n -s e n s e p r e v e n t iv e m e a s u re s ; c e r ta in m e a s u re s , f o r e x a m p le , d e s ig n e d t o w a r d o ff t h e s u b te r ra n e a n te r m it e s a re q u it e useless as a p ro ­ t e c t io n a g a in s t t h e d r y -w o o d t e r m it e .

P r e v e n t i v e M e a s u r e s a g a i n s t F u n g u s A t t a c k .

I n c o n s id e rin g a d e q u a te m e a s u re s f o r th e p r e v e n t io n o f fu n g u s a tta c k , t h e fo llo w in g m a t e r ia l fa c ts m u s t b e b o rn e in m in d :—

( a ) T h a t h e a t, a ir , a n d m o is tu re a re n e c e s s a ry f o r th e d e v e lo p m e n t o f fu n g i.

(b) T h a t a g r e a t excess o f a n y o f th e s e is d e le te rio u s t o fu n g i.

(c) T h a t , g e n e r a lly s p e a k in g , s o ftw o o d s a re m o re lia b le t o a t t a c k th a n h a rd w o o d s , a n d s a p w o o d t h a n h e a r tw o o d .

T h e fo llo w in g a re th e m a in p r e v e n t iv e m e a s u re s w h ic h s h o u ld be g e n e ra lly a d o p te d :—

1. T i m b e r s i n C o n t a c t w i t h t h e G r o u n d : e .g ., P o s t s , P o l e s a n d Wo o d e n F o u n d a t i o n s o f B u i l d i n g s .

( a ) U s e o n ly a ll- h e a r t tim b e r s o f p r o v e d re s is ta n c e to fu n g u s a tta c k

( v i d e t a b le in A p p e n d ix I ) .

(b ) U s e t im b e r w h ic h h as b e e n p r o p e r ly t r e a t e d w i t h a n e ffe c tiv e p r e s e rv a tiv e .

2. T i m b e r s n o t i n C o n t a c t w i t h t h e G r o u n d : e .g ., H o u s e ^ T i m b e r s .

(1 ) S e l e c t i o n o f T i m b e r .

( a ) U s e o n ly seasoned t im b e r , a n d p r o te c t such t im b e r a g a in s t s u b s e q u e n t d am p n e s s p r io r to use : fu n g u s c a n n o t g ro w o n t im b e r w it h a m o is tu re c o n te n t o f 2 0 p e r c e n t, o r less.

(b ) I f th e t im b e r is t o be e x p o s ed , a n d a t a ll d a n g e r p o in ts w h e re th e re m a y be access t o m o is tu re o r p o o r a i r c ir c u la tio n , use o n ly h e a r t ­ w o o d o f t im b e r o f p ro v e d re s is ta n c e , o r t r e a t e d w o o d .

(c) D o n o t use t im b e r w h ic h a lr e a d y show s a n y signs o f fu n g u s

B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R . G 7

(2 ) C o n s t r u c t i o n M e a s u r e s .

( a ) T a k e e v e r y p re c a u tio n to a v o id access o f m o is tu re t o t h e t im b e r . I n o th e r t h a n t im b e r - f r a m e houses a d e q u a te d a m p -p ro o fin g is e s s e n tia l w h e re t im b e r com es in t o c o n ta c t w i t h o th e r m a t e r ia ls o f c o n s tr u c tio n , w h ic h a re in tr o d u c e d in a w o t s ta te o r w h ic h th e m s e lv e s a re n o t d a m p - p ro o f.

( b ) A v o id a n y d a n g e r o f c o n d e n s a tio n o f m o is tu re o n t h e in t e r n a l surfaces o f w a lls , w h ic h m a y s t a r t fu n g u s g r o w th b e h in d s k ir tin g - b o a rd s , e tc .

(c) E n s u r e , so f a r as is p o s s ib le —e . g . , in th e case o f w o o d flo o rs — - a d e q u a te a i r c irc u la tio n .

( d ) I n th e case o f w o o d flo o rs la id o n c o n c re te , c o n s tru c t a n u p p e r t h i n la y e r o f im p e rm e a b le c o n c re te , a n d c o v e r t h e c o n c re te a f t e r i t has d rie d w i t h a t h ic k , d a m p -p r o o f, b itu m in o u s c o a t.

(e) D o n o t a llo w t h e use o f lin o le u m o v e r wro o d flo o rin g w h ic h is la id d ir e c t t o c o n c re te , u n t i l t h e house h as h a d t i m e t o d r y o u t . A t a n y t im e t h e use o f a c o v e rin g o v e r th e w h o l e flo o r a re a , w h ic h p re v e n ts th e access o f a ir a n d , w h e n w a s h e d , a llo w s w a t e r t o a c c u m u la te b e lo w , is d a n g e ro u s .

( / ) W h e n u sin g t r e a te d w o o d , p r e -f a b r ic a tio n is d e s ira b le b e fo re t h e a p p lic a tio n o f t r e a t m e n t ; i f p o s s i b l e , a l l s u r f a c e s s u b s e q u e n t l y e x p o s e d b y c u t t i n g o r p u n c t u r i n g m u s t b e b r u s h t r e a t e d w i t h p r e s e r v a t i v e .

( g ) A lw a y s re m o v e s h a v in g s , so il, a n d d e b ris f r o m s u rfa c e c o n c re te , to g e th e r w i t h pieces o f w o o d e m p lo y e d d u r in g e x c a v a t io n a n d s h u t t e r ­ in g u sed f o r c o n c re te w o r k .

P r e v e n t i v e Me a s u r e s a g a i n s t D r y - W o o d T e r m i t e s , P o w d e r - P o s t a n d O t h e r B e e t l e s .

T h e d r y -w o o d t e r m it e c a n n o t be c o n tro lle d b y c o n s tr u c tio n m e a s u re s , as i t does n o t n e e d c o n ta c t w i t h th e g ro u n d . T h e b e s t p r e v e n t iv e m e a s u re s a re :—

(a ) U s e o n ly a ll-h e a r t tim b e r s o f p ro v e d re s is ta n c e to t e n n i t e a t t a c k

( v i d e t a b le in A p p e n d ix I ) .

( b ) U s e t im b e r w h ic h has b e e n p r o p e r ly t r e a te d w ith ' a n e ffe c tiv e p re s e rv a tiv e .

P r e v e n t i v e M e a s u r e s a g a i n s t S u b t e r r a n e a n T e r m i t e s .

1. T i m b e r s i n C o n t a c t w i t h t j i e G r o u n d .

( a ) U s e o n ly t im b e r o f p ro v e d re s is ta n c e to t e r m i t e a t t a c k ( v i d e

ta b le in A p p e n d ix I ) .

( b ) U s e t im b e r w h ic h h as b ee n p r o p e r ly t r e a te d w i t h a n e ffe c tiv e p r e s e rv a tiv e .

2 . T i m b e r s n o t i n C o n t a c t w i t h t h e Gr o u n d .

I t is im p o r t a n t to r e m e m b e r t h a t s u b te r ra n e a n t e r m it e s e n te r b u ild in g s b y m e a n s o f c ra c k s in c o n c re te o r m a s o n r y w a lls , t h r o u g h t im b e r s , o r b y m e a n s o f t h e ir tu b e s b u i l t o v e r th e s e m a te r ia ls . T h e y m a y a ls o b u ild t h e i r

tu b e s a lo n g th e s u rfa c e o f p ip e s , fe n c e -p o s ts , tre llis e s , e tc ., a n d

f a i n e n tra n c e . P r o p e r m e th o d s o f c o n s tru c tio n c a n i n t h e case o t s im p le b u ild in g s p r o h ib it e n t ir e ly th e e n tra n c e o f s u b te r ra n e n a n t e r m ite s .

T h e fo llo w in g is a s u m m a r y o f som e o f th e m e a s u re s re c o m m e n d e d m th e

U . S . A . '

(1 ) B u ild in a m a n n e r w h ic h w i l l p r e v e n t th e e n t r y o f te r m it e s fro m th e soil.

(2 ) T h e fo u n d a tio n s o f b u ild in g s s h o u ld b e o f c o n c re te , m a s o n ry la id in c e m e n t, o r o f p r o p e r ly t r e a t e d t im b e r , o r o f t im b e r o f p ro v e d re s is ta n c e to te r m it e s .

(3 ) P r o v id e a ll fo u n d a tio n w a lls , p o sts, o r p ie rs w i t h m e t a l te r m it e s h ie ld s b e lo w th e w o o d t o b e p r o te c te d , c o n s is tin g o f a n o n -c o rro d in g s h e e t o f m e t a l p r o je c t in g h o r iz o n t a lly a t le a s t 2 in c h e s , a n d th e n t u r n e d d o w n w a r d s f o r a n a d d it io n a l 2 in c h e s a t a n a n g le o f 4 5 ° ; a ll jo in t s s h o u ld b e lo c k e d , a n d p r e fe r a b ly s o ld e re d w i t h corners m a d e t i g h t . B e d a l l w o o d p o s ts, p la te s , e tc ., o n a n e w ly la id m o r t a r cap a b o v e t h e fo u n d a tio n .

(4 ) W h e r e p ip e s e x te n d t h r o u g h c o n c re te flo o rs o r m a s o n r y w a lls , a t i g h t j o i n t m u s t b e s e c u red a b o u t t h e m w i t h c e m e n t m o r t a r . P ip es e x te n d in g i n t o t h e g r o u n d s h o u ld b e p ro te c te d b y a d o w n w a rd -s lo p in g c o lla r s o ld e re d t o t h e p ip e s a b o u t 18 in c h e s a b o v e g r o u n d w i t h a h o r i­

z o n t a l p r o je c t io n o f a t le a s t 3 in c h e s a t t h e i r lo w e r edge.

(5 ) T h e s o il b e n e a th a n d a ro u n d t h e b u ild in g s h o u ld b e p ro v id e d w i t h a d e q u a te d ra in a g e .

(6 ) D e b r is a n d s h u t te r in g s h o u ld b e c le a re d f r o m u n d e r floors, p o rc h e s , a n d a r o u n d f o u n d a tio n w a lls , a n d n o t u s e d as f i l l i n p la c e o f e a r t h . R e m o v e a ll t r e e -s tu m p s a n d ro o ts u n d e r a n d a ro u n d th e b u ild in g .

(7 ) F e n c e s , tre llis e s , e t c ., s h o u ld b e k e p t a t le a s t 2 in c h e s a w a y fro m t h e b u ild in g .

I n t h e case o f b u ild in g s ra is e d o ff t h e g ro u n d , i t is a s o u n d p ra c tic e n o t to jo in t h e ste p s t o t h e b u ild in g , b u t t o s e p a ra te t h e t w o b y a g a p o f 2 inches.

R e g u la r in s p e c tio n s to lo o k f o r ru n w a y s a re d e s ira b le .

M

R

.

A t t a c h b y F u n g u s .

(1 ) R e m o v e a n d b u r n a ll in fe c te d m a t e r ia l, a n d re p la c e w i t h p ro p e rly t r e a t e d t im b e r .

(2 ) I f n o t to o c o s tly , e lim in a t e th e c o n d itio n s o f d a m p ca u s in g th e f u n g a l a t t a c k .

A t t a c k b y D r y - W o o d T e r m i t e s .

(1 ) A l l s tr u c t u r a lly u n s a fe m a te r ia ls s h o u ld be re m o v e d a n d b u r n t . (2) I n th e case o f w o o d l e f t i n s i t u , p o is o n d u s ts , such as P a r is G re e n , m a y be b lo w n in t o o p e n in g s m a d e in t o t h e g a lle rie s o f t h e t e r m ite s , a n d th e o p e n in g s t h e n p lu g g e d . A s t h e te r m it e s lic k e a c h o th e r a n d also con sum e d e a d m e m b e rs o f th e c o lo n y , t h e w h o le c o lo n y m a V b e e v e n ­ t u a l l y d e s tro y e d .

6 8 B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R .

B R O O K S : T H E P R E S E R V A T I O N O E T I M B E R . 6 9

(3 ) A l t e r n a t i v e ly , t h e w o o d m a y be fu m ig a t e d b y p la c in g a w a d o f c o tto n s o a k e d in c a rb o n b is u lp h id e o v e r a n o p e n in g to t h e g a lle rie s a n d c o v e re d b y a d o u b le she e t o f w e t n e w s p a p e r m a d e t o a d h e re closely to t h e w o o d .

(4 ) In f e c te d f u r n it u r e m a y be e x p o s ed to le t h a l te m p e r a tu r e s ( 1 2 0 - 1 5 0 ° F . ) , o r f u m ig a te d in a n a i r - t i g h t c o n ta in e r w i t h som e f u m ig a n t such as c a rb o n b is u lp h id e .

T h e use o f a rs e n ic a l-d u s t poisons in d w e llin g -h o u s e s is n o t re c o m m e n d e d , o w in g t o th e a b i l i t y o f c e r ta in fu n g i, w h ic h m a y be p re s e n t in th e t e r m it e g alle rie s , to a b s o rb a rs e n ic a n d la t e r e m it i t in th e fo r m o f d ie th y la r s in e , w h ic h is a h ig h ly t o x ic gas, d a n g e ro u s t o h u m a n b ein gs.

A t t a c k b y S u b t e r r a n e a n T e r m i t e s .

(1 ) A l l a v e n u e s b e tw e e n th e g ro u n d a n d th e m a t e r ia l t o b e p r o te c te d m u s t be closed b y p la c in g b a r rie r s o f m e t a l, c o n c re te , o r t r e a t e d w o o d . A l l t e r m ite s c u t o ff f r o m th e g r o u n d w i l l d ie .

(2 ) A l l s t r u c t u r a lly u n s o u n d w o o d m u s t be re m o v e d a n d b u r n t . (3 ) T h e g ro u n d m a y b e p o is o n e d a t a ll p o in ts w h e r e r u n w a y s e m e rg e ; poisons re c o m m e n d e d b y a u t h o r itie s a re a 10 p e r c e n t, s o lu tio n o f s o d iu m a r s e n it e ; le a d a rs e n a te a t t h e r a t e o f 5 lb . p e r 1 0 0 0 sq. f t . ; a m i x t u r e o f 1 p a r t creo sote t o 3 p a r ts k e r o s in e ; a n d c a rb o n b is u lp h id e e m u ls io n .

(4 ) In t r o d u c e p o is o n d u s ts o r f u m ig a n ts , as in t h e case o f d r y -w o o d te r m ite s , in t o t e r m it e g a lle rie s in w o o d w h ic h m u s t b e l e f t i n c o n ta c t w i t h th e g ro u n d .

W

P

.

I n th e fo re g o in g d e s c rip tio n o f m e a s u re s t o be a d o p te d f o r th e p r e v e n t io n o f fu n g u s a n d t e r m it e a t t a c k fre q u e n t m e n tio n h as b e e n m a d e o f t h e use o f w o o d p r o p e r ly t r e a te d w i t h e ffe c tiv e p re s e rv a tiv e s . T h e use o f w o o d p r e ­ s e rv a tiv e s is, u n f o r tu n a t e ly , a lm o s t n o n -e x is te n t in T r i n i d a d ; w h e n w o o d p re s e rv a tiv e s a r e used , t h e y a re o fte n so u n in t e llig e n t ly a p p lie d as c o m p le te ly

t o n u l l i f y t h e ir v a lu e a n d w a s te th e m o n e y s p e n t o n th e m .

T h e fir s t im p o r t a n t p o in t t o re m e m b e r in c o n n e c tio n w i t h w o o d p re s e r v a ­ t io n is t h a t s a tis fa c to ry re s u lts d e p e n d o n t h e m a in te n a n c e o f a n u n b r o k e n

c o a tin g o f p r e s e r v a tiv e ; as soon as t h e c o a tin g is b r o k e n a t a n y p o in t , u n t r e a te d w o o d is e x p o s ed t o in s e c t o r fu n g u s a t t a c k a n d t h e r e m a in in g c o a tin g is re n d e re d useless, since a t t a c k c a n p ro g res s b e h in d i t . C o nse­

q u e n t ly tim b e r s e x p o s ed t o s p lit tin g f r o m a tm o s p h e r ic c o n d itio n s o r to m e c h a n ic a l i n j u r y re q u ir e a f a r d e e p e r p e n e tr a tio n o f p r e s e r v a tiv e t h a n tim b e r s w h ic h , a f t e r b e in g p la c e d in p o s itio n , a re n o t so e x p o s e d .

T h e second im p o r t a n t p o in t to re m e m b e r is t h a t t h e p e n e tr a tio n o f t h e p re s e rv a tiv e in t o seasoned t im b e r is f a r g r e a te r t h a n in t o g re e n t im b e r , a n d in t o s a p w o o d t h a n h e a r tw o o d . G e n e r a lly s p e a k in g , p e n e t r a t io n is b e t t e r w it h s o ftw o o d s t h a n h a rd w o o d s .

T h u s th e a d o p tio n o f p ro p e r w o o d p re s e r v a tio n e n a b le s t h e c o n fid e n t use o f t im b e r c o n ta in in g s a p w o o d a n d o f n o n -d u r a b le species o f t im b e r , w h ic h , u n t r e a te d , a re p ro n e to r a p id d e c a y o r d e s tr u c tio n .

7 0 B R O O K S : T H E P R E S E R V A T I O N O P T I M B E R .

M

T

.

N o p r e s e rv a tiv e c on fers c o m p le te i m m u n i t y in d e fin ite ly , a n d , p ro v id e d t h a t a p re s e rv a tiv e o f p ro v e d e ffic a c y is used , th e m e th o d o f t r e a t m e n t is, s u b je c t to c e r ta in c o n s id e ra tio n s re fe rr e d t o la te r , m o re im p o r t a n t t h a n th e choice o f p re s e rv a tiv e .

T h e r e a re fiv e m e th o d s o f t r e a t m e n t — v iz ., b ru s h in g , s p r a y in g , d ip p in g ,

“ o p e n t a n k , ” a n d p re s s u re, o f w h ic h th e fir s t is th e le a s t effic a c io u s a n d th e la s t th e m o s t.

B r u s h T r e a t m e n t has t h e a d v a n ta g e o f e x tr e m e s im p lic it y , b u t p e n e tr a ­ t io n is u s u a lly v e r y s u p e rfic ia l. A t l e a s t t w o coa ts s h o u ld be g iv e n , th e second b e in g a p p lie d a f t e r th e fir s t is d r y . I n th e case o f creo sote ty p e p re s e rv a tiv e s , b e t t e r p e n e tr a tio n is se c u red i f th e l iq u id is a p p lie d h o t.

S p r a y i n g h as m u c h t h e sa m e e ffe c tiv e n e s s as b ru s h in g .

D i p p i n g i n e ith e r h o t o r c o ld p r e s e r v a tiv e is b e t t e r t h a n b ru s h in g , b u t a g a in o n ly l ig h t p e n e t r a t io n is s ecured .

A l l t h e a b o v e m e th o d s s h o u ld , i f lo n g life is a im e d a t , be c o n fin e d to tim b e r s w h ic h a re t o b e p r o te c te d f r o m e x p o s u re to a tm o s p h e r ic c o n d itio n s a n d t o m e c h a n ic a l i n j u r y , a n d t o r e p a ir in g th e d a m a g e d o n e t o tre a te d t im b e r b y s u b s e q u e n t fa b r ic a t io n .

T h e Op e n - t a n k T r e a t m e n t is f a r s u p e rio r to b ru s h in g , s p r a y in g , o r d ip p in g ; p r o v id e d t h e w o o d is seasoned, g o o d p e n e tr a tio n is s e c u red , e x c e p t in th e case o f t im b e r s w h ic h a re h ig h ly r e s is ta n t to im p r e g n a t io n . S u c h tim b e rs , h o w e v e r, m a y p r o v e r e f r a c t o r y e v e n t o p re s s u re t r e a t m e n t .

T h e t h e o r y o f t h e m e t h o d is as fo llo w s : A i r - d r y w o o d c o n ta in s m in u te a i r spaces, w h ic h m a y o c c u p y u p t o n e a r ly 5 0 p e r c e n t, o f it s v o lu m e . W h e n a i r - d r y w o o d is im m e rs e d in a liq u id , w h ic h is t h e n h e a te d , th e a ir e x p a n d s , a n d som e o f i t is d r iv e n o u t o f t h e w o o d . W h e n t h e liq u id is a llo w e d t o c o o l, t h e a i r l e f t i n t h e w o o d c o n tra c ts a g a in , fo r m in g a p a r tia l v a c u u m , a n d t h e l iq u id is d r a w n i n t o t h e w o o d . I n t h e case o f g re e n w oo d, th e spaces, w h ic h i n a i r - d r y w o o d a re f ille d w i t h a ir , c o n ta in w a t e r ; th e e x p a n s io n o f th is w a t e r u n d e r h e a t is r e l a t i v e l y s m a ll, a n d c o n s e q u e n tly b u t l i t t l e o f t h e p r e s e r v a tiv e w i l l b e d r a w n in t o t h e w o o d d u r in g t h e cooling p e rio d .

T h e p la n t re q u ir e d f o r th is m e th o d is s im p le a n d in e x p e n s iv e , a n d does n o t r e q u ir e t e c h n ic a lly s k ille d o p e ra to rs . I t consists o f a t r e a t in g - t a n k m a d e o f ir o n o r m i l d s te e l I in c h t h ic k , o f d im e n s io n s s u ita b le f o r th e typ e s o f t im b e r t o b e t r e a t e d ; a u s e fu l s ize d t a n k w o u ld b e 2 0 f e e t X 4 f e e t X 4 fe e t. T r e a t in g - t a n k s s h o u ld b e d e e p a n d n a r r o w , r a t h e r t h a n w id e a n d s h a llo w , in o rd e r to m in im iz e e v a p o r a t io n losses.

T h e t r e a t i n g - t a n k m u s t be p r o v id e d w i t h som e m e a n s o f h e a tin g , such as a s y s te m o f s te a m coils le a d in g f r o m a b o ile r, o r a flu e r u n n in g th e w h o le le n g th b e n e a th , in w h ic h a fire can be l i t ; a lt e r n a t iv e ly , i t m a y be e le c tr i­

c a lly h e a te d .

T h e t r e a t in g - t a n k s h o u ld also be p r o v id e d w i t h s te e l g ird e rs a t th e b o t to m o n w h ic h th e t im b e r c a n re s t, a n d th u s a llo w c ir c u la t io n o f th e creo sote. I t is d e s ira b le also to p r o v id e w o o d e n c overs w i t h w h ic h to close t h e t a n k a n d m in im iz e e v a p o r a tio n . A d r a in - p lu g s h o u ld be p r o v id e d in th e b o tto m o f th e t a n k t o a llo w e m p ty in g f o r c le a n in g o r o th e r p u rp o se s .

" he t a n k is u s u a lly p a r t l y s u n k in a p i t w i t h a space a ro u n d th e sides to

B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R . 71

a llo w fre e c ir c u la tio n o f a i r f o r c o o lin g a n d access f o r in s p e c tio n . I t m a y be p ro v id e d w i t h a s tp ra g e t a n k a n d p u m p , o r m e r e ly a p la t f o r m o n w h ic h d ru m s o f t h e p r e s e rv a tiv e c a n be p la c e d , a n d f r o m w h ic h th e l iq u id c a n r u n d ir e c t in t o t h e t a n k .

A t one e n d o f th e t a n k a d r a in in g - ta b le s h o u ld b e c o n s tr u c te d la rg e e n o ug h t o h o ld a n y lo a d c o m in g f r o m th e t r e a t in g - t a n k . T h e t a b le c a n d r a in b a c k in t o th e t a n k o r in t o a d r a in le a d in g to th e s to ra g e t a n k .

A s im p le fo r m o f g a n t r y a n d lif t in g - w in c h s h o u ld r u n t h e e n t ir e le n g th o f th e p la n t t o f a c ilit a t e th e h a n d lin g o f t h e lo a d s o f t im b e r . T h e la th s a re u s u a lly h e ld in som e fo r m o f c ra d le , w h ic h is lo w e re d in t o t h e t a n k f o r t r e a t ­ m e n t. T h e t im b e r is -s ta c k e d in th e c ra d le w i t h s trip s o f w o o d \ in c h t h i c k b e tw e e n each la y e r t o e n s u re fre e c ir c u la tio n o f t h e liq u id , a n d h e a v y w e ig h ts o f o ld ir o n a re p la c e d o n t h e to p t o e n s u re c o m p le te s u b m e rs io n o f th e lo a d . A t h e r m o m e te r c o m p le te s th e e q u ip m e n t.

T h e m e th o d o f o p e ra tio n is as fo llo w s : th e c ra d le c o n ta in in g t h e lo a d o f t im b e r is lo w e re d in t o th e t a n k , a n d th e p r e s e r v a tiv e is t h e n h e a te d t o a te m p e r a tu r e o f 1 8 0 -2 2 0 ° F . T h is .t e m p e r a t u r e is m a in t a in e d f o r v a r y in g p erio d s , a c c o rd in g t o t h e size o f t im b e r b e in g t r e a t e d a n d t h e a m o u n t o f a b s o rp tio n d e s ire d . T h e p r e s e rv a tiv e is t h e n a llo w e d t o c o o l, c a r e b e i n g t a k e n t h a t t h e t i m b e r i s c o m p l e t e l y s u b m e r g e d d u r i n g t h e c o o l i n g p e r i o d , w h i c h i s a l s o t h e a b s o r p t i o n p e r i o d ; t h e t im b e r is t h e n re m o v e d a n d a llo w e d t o d ra in . T h e h e a tin g p e r io d u s u a lly o ccu pies a b o u t 4 h o u rs , a n d th u s t h e o p e ra to r n e e d o n ly b e i n a tte n d a n c e f o r t h a t p e r io d , as th e r e is n o t h in g f u r t h e r f o r h im t o d o a f t e r t u r n in g o ff t h e h e a t. T h e a b s o rp tio n o f t h e p re s e rv a tiv e c a n b e re g u la te d b y le n g th e n in g t h e h e a tin g p e r io d .

T h e process c a n b e s peed ed u p b y in s t a llin g a b a t t e r y o f t w o t a n k s , o n e t o c o n ta in t h e h o t p r e s e rv a tiv e , a n d t h e o th e r t h e c o ld . W i t h t h is p la n t th e t im b e r c a n b e tra n s fe rr e d , a f t e r a s u ffic ie n t h e a tin g p e r io d , f r o m t h e h o t t a n k t o th e c o ld , w h e re u p o n a n e w lo a d c a n be p la c e d i n t h e h o t t a n k .

F o r th e b u t t t r e a t m e n t o f posts a n d poles— i.e ., t h e t r e a t m e n t o n ly o f t h a t p a r t w h ic h is in c o n ta c t w i t h a n d n e a r t h e g r o u n d — a v e r y s im p le p la n t c a n be c o n s tru c te d , c o n s is tin g o f a n o il d r u m p r o v id e d w i t h a b r ic k fu rn a c e a n d a flu e .

I t m a y be o f in te re s t to re c o rd t h a t i n th e case o f r a i l w a y sleep ers m a d e f r o m fo u rte e n d iffe r e n t species o f lo c a l h a rd w o o d s , a n a v e ra g e a b s o r p tio n o f 4 lb . o f creosote p e r c u b ic f o o t w a s o b ta in e d b y t h is m e t h o d ; a lo n g e r seasoning p e r io d w;o u ld h a v e p ro d u c e d e v e n b e t t e r re s u lts .

P r e s s u r e T r e a t m e n t is t h e m o s t e ffe c tiv e o f a l l m e th o d s o f a p p ly in g p re s e rv a tiv e s : i t is u s u a lly c o n s id e red e c o n o m ic a l o n ly w h e r e c o n s id e ra b le q u a n titie s o f lu m b e r h a v e t o b e t r e a te d , as i t in v o lv e s a s o m e w h a t e la b o r a te a n d e x p e n s iv e p la n t c o m b in e d w i t h s k ille d o p e ra tio n . I n b r ie f, th e p la n t consists o f a s to ra g e t a n k , a t r e a t i n g - t a n k o r c y lin d e r , v a c u u m a n d p re s s u re p u m p s , a n d a s te a m -r a is in g p la n t .

I n th e “ f u ll- c e ll ” process t h e t im b e r is p la c e d in t h e t r e a t i n g - t a n k , a n d a v a c u u m is a p p lie d t o d r a w as m u c h a ir as p o s s ib le f r o m t h e cells o f t h e w o o d . T h e p re s e r v a tiv e is t h e n r u n i n t o t h e t a n k , a n d a p re s s u re o f 1 G O - 175 lb . p e r s q u a re in c h is a p p lie d to fo rc e th e p r e s e r v a tiv e in t o t h e w o o d . A s a re s u lt o f th e p r e lim in a r y v a c u u m t r e a t m e n t t h e p r e s e r v a tiv e flo w s in t o , a n d re m a in s in , t h e w o o d cells.

I n th e “ e m p ty -c e ll ” process t h e t im b e r is s u b je c te d t o a p r e lim i n a r y

p ressure b e fo re th e a p p lic a tio n o f th e p r e s e rv a tiv e , a n d th e l a t t e r is th e n fo rc e d in t o th e w o o d u n d e r p re s s u re. W h e n t h e p re s s u re is re le a s e d , e e x p a n d in g a ir in th e cells forces t h e p r e s e r v a tiv e o u t o f th e cells, le a v in g o n ly th e cell w a lls c o a te d w i t h t h e p re s e r v a tiv e . A f in a l d r y in g v a c u u m is th e n a p p lie d .

P r e - t r e a t m e n t .— I n th e case o f tim b e r s w h ic h a re re s is ta n t t o im p r e g n a ­ tio n e . g . , d o u g la s fir — a n d w h e re g o o d p e n e tr a tio n is e s s e n tia l, a p re - t r e a t m e n t b y in c is io n is o fte n p ra c tis e d . T h e t im b e r is p assed u n d e r a re v o lv in g d r u m f it t e d w i t h r e g u la r ly s p a c e d k n iv e s , w h ic h in c is e gashes in to th e t im b e r o f th e r e q u ir e d d e p th . T h is o p e r a tio n assists s u b s e q u e n t p e n e tr a tio n .

W o o n

P

.

P r e s e r v a tiv e s c a n be b r o a d ly classed in t o th r e e m a in g ro u p s : O il p re ­ s e rv a tiv e s , w a te r -s o lu b le s a lts , a n d s o lv e n t t y p e p re s e rv a tiv e s .

O i l P r e s e r v a t i v e s .

T h e m o s t im p o r t a n t o f th e s e a re c o a l- ta r a n d creosote.

C o a l- t a r is n o t v e r y s a tis fa c to r y : i t does n o t p e n e tr a te w o o d , b u t fo rm s a s u rfa c e c o a tin g w h ic h m a y e v e n t u a lly assist d e c a y b y s e a lin g u p th e m o is tu r e i n t h e w o o d .

B y creo sote as a w o o d p r e s e r v a tiv e is u n d e rs to o d a c o a l- ta r creosote o i l ; i t is a d is t illa t e o f c o a l- ta r p ro d u c e d b y h ig h - t e m p e r a tu r e c a rb o n iz a tio n o f b itu m in o u s c o a l. I t s h o u ld c o m p ly w i t h t h e s p e c ific a tio n o f t h e B r itis h S t a n d a rd s I n s t i t u t i o n (see A p p e n d ix I I ) .

A h a lf - a n d - h a lf m i x t u r e o f creo sote w i t h d ie s e l o il is ju s t as e ffe c tiv e as p u r e c re o s o te , f r o m t h e p r e s e rv a tio n p o in t o f v ie w , p e n e tr a te s w o o d b e t t e r , a n d is c o n s id e ra b ly c h e a p e r i n v ie w o f th e lo w cost o f th e d iesel o il.

T h e a d v a n ta g e s o f c reo sote a re its e x tr e m e t o x i c i t y a n d it s p e rm a n e n c e in t h e w o o d e v e n w h e n e x p o s e d t o r a i n ; its d is a d v a n ta g e s a re its s m e ll, its d a r k c o lo u r, it s l i a b i l i t y t o creep o n to a n d s ta in a d jo in in g m a t e r ia l, th e fa c t t h a t i t c a n n o t b e p a in te d o v e r , a n d , b e in g ip l iq u id f o r m , its b u lk .

I t s e x c e lle n c e as a p r e s e r v a tiv e is u n r iv a lle d , a n d w h e re it s d is a d v a n ta g e s d o n o t m a t t e r —e . g . , f o r e x te r io r t im b e r s i n c o n ta c t w i t h t h e g ro u n d , such as p o sts, p o le s , sleepers, e tc .— a b e t t e r c ho ice c a n n o t b e m a d e .

T h e r e a re v a rio u s p r o p r ie t a r y p r e s e rv a tiv e s p r e p a r e d f r o m t a r o il, w h ic h a re e ffic ie n t, c le a n e r, a n d o f less p u n g e n t s m e ll t h a n o r d in a r y c reo sote;

th e y a re , h o w e v e r, m o re c o s tly .

W a t e r - S o l u b l e S a l t s .

T h e salts c h ie fly c o n c e rn e d a re c o p p e r c h r o m a te , c o p p e r s u lp h a te , s o d iu m flu o rid e , m e r c u r ic c h lo rid e , z in c c h lo rid e , z in c s u lp h a te , a n d zinc m e ta -a r s e n ite . S e v e ra l p r o p r ie t a r y b ra n d s o f p r e s e rv a tiv e s e m p lo y one o r m o re o f the s e s a lts , a n d in som e a n a t t e m p t h as b e e n m a d e t o f i x th e p re s e rv a tiv e p rin c ip le s in th e w o o d so t h a t t h e y c a n n o t be le a c h e d o u t.

T h e a d v a n ta g e s of w a te r -s o lu b le s a lts , p a r t i c u l a r l y f o r b u ild in g s , a re : t h e ir r e la t iv e ly s m a ll b u lk in s o lid f o r m , t h e ir la c k o f s m e ll a n d (u s u a lly ) c o lo u r, a n d th e fa c ts t h a t th e y d o n o t cre e p a n d s ta in a d jo in in g m a t e r ia l, a n d c a n b e p a in te d o v e r. I n a d d itio n , z in c c h lo rid e t o som e e x t e n t i n ­ creases th e fire -re s is ta n c e o f w o o d . T h e i r d is a d v a n ta g e lies in t h e ir 7 2 BRO OKS : TH E PR ESER V A T IO N OF T IM B ER .

B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R . 7 3

l ia b ilit y to be le a c h e d o u t b y r a in a n d t h a t som e o f t h e m h a v e a c o rro s iv e ' effe c t o n m e ta ls , n e c e s s ita tin g a w o o d e n t a n k f o r t r e a t m e n t . T h is does n o t

a p p ly t o z in c c h lo rid e , w h ic h , in c id e n t a lly , h as a g o o d re c o rd in P a n a m a .

S o l v e n t - T y p e P r e s e r v a t i v e s .

T h e s o lv e n t-ty p e p re s e r v a tiv e consists o f a t o x ic c h e m ic a l d is s o lv e d in a v o la tile o il o r s p ir it s o lv e n t, w h ic h , a f t e r t r e a t m e n t , e v a p o ra te s a n d le a v e s th e to x ic c h e m ic a l in th e w o o d . T h e t o x ic c h e m ic a ls u se d in c lu d e m e t a llic salts o f o rg a n ic acids such as n a p h th e n ic a n d o le ic a c id s ; p h e n o ls such as p- n a p h th o l, c h lo rin a te d p h e n o ls a n d c h lo r in a te d h y d ro c a rb o n s , s u c h as c h lo rin a te d n a p h th a le n e . I t m a y b e o f in t e r e s t t o re c o rd t h a t lo c a l te s ts a re n o w b ein g c o n d u c te d o n t im b e r t r e a te d lo c a lly b y t h e o p e n - t a n k m e th o d w ith cop p e r a n d m e rc u ric n a p h th a n a te s p ro d u c e d b y T r i n i d a d L e a s e h o ld s , L tc L , w ith , so f a r , m o s t e n c o u ra g in g re s u lts .

T h e a d v a n ta g e s o f th is t y p e o f p re s e r v a tiv e a re t h e i r h ig h t o x i c i t y a n d good p e n e t r a t io n ; th e d is a d v a n ta g e s a re t h e h ig h cost, a n d , in som e cases, t h e ir in f la m m a b ility p r io r t o b e in g a p p lie d t o t h e w o o d . T h e o p e n - t a n k t r e a tm e n t w a s , h o w e v e r, a p p lie d w it h o u t d a n g e r i n t h e case o f t h e c o p p e r a n d m e rc u ric n a p h th a n a te s r e fe rr e d t o a b o v e .

C

P

M

T

.

F r o m th e fo re g o in g b r i e f a c c o u n t o f w o o d p r e s e rv a tiv e s a n d t h e m e th o d s o f t h e ir a p p lic a tio n , i t is c le a r t h a t th e cho ice o f p re s e r v a tiv e a n d m e t h o d o f tr e a tm e n t w i l l v a r y a c c o rd in g t o a n u m b e r o f fa c to rs e . g . :—

(1) T h e species o f t im b e r — its n a t u r a l d u r a b i l i t y a n d it s re s is ta n c e o r o th e rw is e to im p re g n a tio n .

(2) T h e use to w h ic h t h e t i m b e r is t o b e p u t , a n d t h e c o n s e q u e n t degree o f d a n g e r t o w h ic h i t w i l l b e e x p o s e d . C le a r ly t im b e r s i n c o n t a c t w ith th e g ro u n d a n d e x p o s e d -to t h e w e a th e r r e q u ir e a d e e p e r a n d m o re th o ro u g h im p re g n a tio n t h a n i n t e r io r tim b e r s .

(3) T h e le n g th o f life w h ic h i t is d e s ire d t h a t t h e t i m b e r s h o u ld h a v e .

(4) T h e cost o f th e m e th o d o f t r e a t m e n t a n d o f t h e p r e s e r v a tiv e r e la tiv e to th e v a lu e o f th e in c re as e o f life o b ta in e d .

(5) T h e a n n u a l a m o u n t o f t im b e r u t iliz e d f o r n e w w o r k s . (6) T h e a m o u n t o f c a p ita l a v a ila b le f o r t h e e re c tio n o f p la n t .

I n v ie w o f these v a r y in g fa c to rs , i t is n o t p o s s ib le t o l a y d o w n h a r d - a n d - fa s t ru les to g o v e rn th e choice o f p r e s e rv a tiv e a n d m e t h o d o f t r e a t m e n t f o r a ll lo c a l tim b e r-c o n s u m in g in d u s trie s , b u t t h e fo llo w in g r e c o m m e n d a tio n s a re p u t f o r w a r d as a g u id e , w h ic h m a y b e a lte r e d t o s u it i n d i v i d u a l c i r ­ cum stances :—

1. T i m b e r s o t h e r t h a n f o r D w e l l i n g - h o u s e s , O f f i c e s , e t c .

M ethod o f treatm ent.

Pressure or open tan k .

Open tan k , dipping, spraying, or brushing.

Type of tim ber.

( а ) Timbers in contact w ith the ground and/or exposed to the weather and/or abra­

sion—e . g . , posts, poles, bridge-timbers, etc.

(б) Other timbers.

Preservative.

H a lf-a n d -h a lf m ix tu re of creosote and diesel oil.

H a lf-a n d -h a lf m ixture of creosote and diesel oil.

7 4 B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R . 2. T i m b e r s f o r D w e l l i n g - h o u s e s , O f f i c e s , e t c .

(а) Tim bers in contact w ith the ground and /or exposed to the weather and/or abra- - sion.

(б) In te rio r timbers.

W ater-soluble salts—

e . g . , zinc chloride or reliable proprietary preservative.

Water-soluble salts—

e . g . , zinc chloride or reliable proprietary preservative.

Pressure or open tank, followed b y applica­

tions of p ain t.

Open tan k , dipping, spraying, or brushing, followed by ’applica­

tions of paint where indicated.

Co n c l u s i o n.

T h e a d o p tio n o f t h e s im p le p r e v e n t iv e m e th o d s o f c o n s tru c tio n described in th is p a p e r , c o m b in e d w i t h th e use o f w o o d w h ic h h as b ee n p ro p e rly t r e a t e d w i t h a r e lia b le p r e s e r v a tiv e , w o u ld u n q u e s tio n a b ly re s u lt in th e m in im iz a t io n o f th e d e c a y a n d d e s tru c tio n o f t im b e r , in a considerable r e d u c t io n o f e x p e n s e in c u r r e d i n re p a irs a n d re p la c e m e n ts , a n d in a m u ch- n e e d e d e c o n o m y o f t i m b e r c o n s u m p tio n .

Su m m a r y.

T h e n e e d f o r e c o n o m iz in g th e use o f t im b e r b y t h e p ro lo n g a tio n o f its lif e is stressed ; a b r i e f a c c o u n t o f fu n g i, t e r m ite s , a n d o th e r in s e c t pests is g iv e n ; p r e v e n t iv e a n d c o n tro l m e a s u re s a g a in s t th e s e a g e n ts o f d e c a y and d e s tr u c tio n a re d e s c rib e d , a n d in f o r m a t io n as to w o o d p re s e rv a tiv e s a nd t h e m e th o d s o f t h e i r a p p lic a t io n is p re s e n te d . ,

B i b l i o g r a p h y .

The following books and papers have been consulted :—

Adamson, A . M . (1937). “ P re lim in a ry R epo rt on Term ites and T erm ite Damage in T rin id a d , W est Ind ies,” T r o p . A g r i c u l t u r e , V o l. X I V , N o. 5.

B ryan , J. (1931). “ The O pen-tank Process for Antiseptic T reatm ent of Tim ber for Estates, Farm s, Collieries, etc.” , Forest Products Research L aboratory Pamphlet.

B ryan , J. (1932). “ Methods of A p plying Antiseptics,” F o r e s t r y , V ol. V I , No. 1.

Chipp, W . F . (1936). “ The U tiliz a tio n o f the O pen-tank Process for the Preserva­

tiv e T re a tm e n t o f Sleepers in M a la y a ,” M a l a y a n F o r e s t e r , V o l. V , 1936.

F in d la y , W . P. K . (1938). “ D ecay of T im ber and its Prevention,” Departm ent of Scientific and In d u s tria l Research, Forest Products Research Records, No. 27.

Gardner, R . C. B . (1937). “ The Preservative T reatm en t o f Estate and Farm T im ­ ber,” The B ritish W ood Preserving Association, Cir. No. 1.

Groom, P. (1927). “ D ry -ro t in W ood,” D epartm ent of Scientific and Industrial Research, Forest Products Research, B u l l e t i n N o. 1.

Kofoid, C. A ., L ig h t, S. F ., and others (1934). “ Term ites and T erm ite Control,”

U n iversity of California Press.

W o o d P r e s e r v i n g N e w s , January 1933. “ Test House in Panam a Resists A ttack of Termites and Decay.”

B R O O K S : T H E P R E S E R V A T I O N O F T I M B E R . 7 5

Ap p e n d i x I .

R e s i s t a n c e o f L o c a l a n d I m p o r t e d T i m b e r s t o F u n g i a n d T e r m i t e s .

To termites.

F a irly resistant.

V e ry resistant.

Susceptible.

F a irly resistant.

V e ry resistant.

V e ry susceptible.

V e ry susceptible.

F a irly resistant.

F a irly resistant.

V e ry susceptible.

F a irly resistant.

V e ry susceptible.

V e ry resistant.

V e ry susceptible.

V e ry susceptible.

V e ry susceptible.

Susceptible.

Susceptible.

Resistant.

V e ry susceptible.

F a irly resistant.

F a irly resistant.

Resistant.

V e ry resistant.

V e ry resistant.

Susceptible.

V e ry susceptible.

Resistant.

Resistant.

V e ry susceptible.

Susceptible.

V e ry susceptible.

N . B .— (1) In the above table five classes of description are used— viz., resistant,

very resistant, fairly resistant, susceptible, very susceptible.

(2) The table was compiled from d u rab ility tests on untreated tim b er specimens conducted b y the Forest D epartm ent in collaboration w ith the Im p e ria l College of Tropical Agriculture from 1937 onwards.

Species. To fungi.

Acurel. V e ry susceptible.

Balata. V e ry resistant.

Blackheart. F a irly resistant.

Bois lisette. V e ry susceptible.

Bois mulâtre. Resistant.

Cajuea. V e ry susceptible.

Douglas fir. F a irly resistant.

Fiddlewood, black. Susceptible.

Fiddlewood, white. F a irly resistant.

Figuier. V e ry susceptible.

Galba. Susceptible.

Gommier viande biche. Susceptible.

Guatecare. Resistant.

Hogplum. V e ry susceptible.

Laylay. V e ry susceptible.

Mahoe. V e ry susceptible.

Mangrove, red. F a irly resistant.

Mangue, yellow. Resistant.

Mora. Susceptible.

Milkwood. V e ry susceptible.

Olivier, white. F a irly resistant.

Olivier, yellow. F a irly resistant.

Pitch pine (all heart, unbled). V e ry resistant.

Poui. V e ry resistant.

Redwood. Resistant.

Sandbox. F a irly resistant.

Sardine. V e ry susceptible.

Serrette. Susceptible.

Tapana. ^/ Susceptible.

Toporite. V e ry susceptible.

W ild coffee. V e ry susceptible.

WTild chataigne. V e ry susceptible.

Ap p e n d i x I I .

V e r y larg e q u a n titie s o f tim b e r s a re c u t e a c h y e a r b y p e tr o le u m c o m p a n ie s in th e course o f o il e x p lo ita t io n , o f w h ic h n o use is m a d e w h a ts o e v e r.

A tte n tio n is, th e re fo r e , d ir e c te d to th e fo llo w in g suggestion s :—

S u g g e s t i o n s f or t h e I n c r e a s e d U s e o f L o c a l T i m b e r Cu t f o r Cl e a r i n g P u r p o s e s b y P e t r o l e u m C o m p a n i e s .

(1) N o n -d u ra b le s o ftw o o d s , such as m a h o e , c a ju c a , w ild c h a ta ig n e , e tc ., could p ro v id e u s e fu l b o a rd s a n d p la n k s , i f t h e l a t t e r w e re seasoned a n d t h e n g iv e n a p re s e rv a tiv e t r e a t m e n t .

(2) U n se a s o n e d b o a rd s o f lo c a l w o o d s c o u ld b e u se d f o r such p u rp o se s as s h u tte rin g f o r c o n c re te , b o x in g f o r s lu s h -p its , e tc ., in s te a d o f im p o r t e d tim b e r.

(3) S c a n tlin g s o f lo c a l w o o d s c a n b e used a f t e r a s h o rt p e r io d o f case- h a rd e n in g , p ro v id e d t h e y a re n o t r e - c u t in t o s m a lle r d im e n s io n s . S c a n t­

lin g w h ic h is n o t q u ite s tr a ig h t c a n u s u a lly be k e y e d in t o p o s itio n .

(4) T h e a ir-s e a s o n in g o f b o a rd s a n d p la n k s is a s h o rte r a n d s im p le r p r o ­ cess t h a n a p p e a rs t o ’b e g e n e ra lly u n d e rs to o d ; f u l l p a r tic u la r s o f t h e c o rre c t m e th o d can be o b ta in e d f r o m t h e F o r e s t D e p a r t m e n t .