I vi
V___
PHYSICS ABSTRACTS
S E C T I O N A
o f
SCIENCE ABSTRACTS
SECTION A, PHYSICS
SECTION B, ELECTRICAL ENGINEERING
T H E IN S T IT U T IO N O F E L E C T R IC A L E N G IN E E R S
THE PHYSICAL SOCIETY THE AMERICAN PHYSICAL SOCIETY
INSTITUTE OF ELECTRICAL ENGINEERS
ABSTRACTS 3040-3273
■ E dited an d Issued M on th ly by
In Association with
THE AMERICAN
VOLUME 49 D E C E M B E R 1946 NUM BER 588
P R IN C IP A L C O N T E N T S
51 M A T H E M A T I C S
52 A S T R O N O M Y . G E O D E S Y
53 P H Y S I C S
530.1 F u n d a m e n ta ls
530.145 Q u a n tu m th e o r y
531 M e c h a n ic s o f so lid s ■ ■ 53 1 .7 M e c h a n ic a l m e a su re m e n ts 532 M e c h a n ic s o f liq u id s
532.13 V isco sity
532.61 S u r f a c e te n s io n 53 2 .7 4 M o le c u la r a s s o c ia t io n 533 M e c h a n ic s o f g a se s
534 A c o u stic s. V ib ra tio n s
535 O p tic s . R a d i a tio n . S p e c tra
535 .2 4 P h o to m e tr y
535.31 G e o m e t r ic a l o p tic s S 3 5 .3 3 /.3 7 S p e c tra
535.34 A b s o r p tio n
535 .3 7 L u m in e s c e n c e
535.41 In te rf e r e n c e . D if f r a c tio n
535.6 C o lo u r
536 H e a t . T h e rm o d y n a m ic s 53 6 .4 2 T h e r m a l tr a n s f o r m a tio n s
536.7 T h e r m o d y n a m ic s
53 7 /5 3 8 E l e c tric ity . M a g n e tis m . X -ray : C h a rg e d p a rtic le s
537.31 E lec . c o n d u c tiv ity
537.531 X -r a y s
P a g e 335 335 337 337 337 337 338 338 338 339 339 340 340 342 342 342 343 343 344 345 345 345 345 346 346 346 347
P a g e
5 3 7 .5 3 3 E l e c tr o n s 347
5 3 7 .5 6 I o n s 347
537.591 C o sm ic ra y s 348
538 M a g n e tis m 348
539 R a d io a c tiv ity . A to m s . M o le
cules 349
539.13 M o le c u la r s t r u c t u r e 349
539 .1 5 A to m ic s tr u c tu r e 349
5 3 9 .1 6 R a d i o a c tiv ity 35 0
539 .1 8 N e u tr o n s 351
5 3 9 .2 ' S tr u c t u re o f s o lid s 352 5 3 9 .3 /.8 E la s tic ity . S tr e n g t h . R h e o lo g y 352
541 P H Y S I C A L C H E M I S T R Y 353
5 4 1 .1 2 1 /.1 2 8 R e a c tio n k in e tic s 353
541.13 E le c tro c h e m is try 353
5 4 1 .1 4 P h o to c h e m is try 353
541 .1 8 C o llo id s. A d so rp tio n 353
5 4 1 .2 /.6 ’ C h e m ic a l s tr u c tu re 353 54 2 C h e m ic a l p ro c e sse s. A p p a ra tu s 353
5 4 3 /5 4 5 C h em ica l a n a ly sis 35 4
548 C R Y S T A L L O G R A P H Y 35 4
548 .7 3 X -ra y c r y s ta llo g ra p h y 354
55 G E O P H Y S I C S 355
5 5 1 .5 M e te o ro lo g y 35 6
5 7 /5 9 B I O L O G Y 357
61 M e d ic a l sc ie n c e . H u m a n
ph y sio lo g y 357
77 P H O T O G R A P H Y 358
NOTE ON THE ARRANGEMENT OF ABSTRACTS
T h e A b s t r a c ts a r e c la ssifie d b y s u b je c t a c c o r d i n g to th e U n iv e rs a l D e c im a l C la ss ific a tio n , a n d a r r a n g e d in o r d e r o f t h e i r U .D .C . n u m b e rs . (A n a b r id g e d v e rs io n o f th e U .D .C . a c c o m p a n ie s t h e A n n u a l In d e x .) A n a b s t r a c t o f in te r e s t u n d e r m o r e t h a n o n e h e a d h a s a d d itio n a l U .D .C . n u m b e r s , lin k e d b y th e c o lo n sig n , “ : ” e .g . “ 536.21 : 54 8 .0 C o n d u c t io n o f h e a t in c r y s ta l s .” T h e A b s t r a c t is p r in t e d o n c e o n ly , u n d e r th e m a in n u m b e r , e .g . in th e s e c tio n
“ H E A T 5 3 6 ,” b u t C ro s s -re f e r e n c e s a r e in s e r te d u n d e r th e o t h e r n u m b e rs , e.g. “ 5 4 8 .0 : 536.21 see Abstr. 1 2 3 4 " in t h e s e c tio n “ C R Y S T A L L O G R A P H Y 5 4 8 .” T h e s e C ro s s -re fe re n c e s s h o u ld b e in v e s tig a te d , th e r e f o r e , w h e n a p a r t i c u l a r s e c tio n is b e in g s e a r c h e d , a s th e y c o n ta in a d d itio n a l m a t t e r r e le v a n t t o t h a t s e c tio n . A C ro s s -re fe re n c e d o e s no/ r e fe r t o th e A b s t r a c t w h ic h a p p e a r s im m e d ia te ly a b o v e it.
A b s t r a c ts s ig n e d w ith th e f o llo w in g in itia ls h a v e b e e n s u p p lie d b y th e c o u rte s y o f t h e o r g a n iz a tio n s n a m e d :
“ B .A .” = B r itis h A b s tr a c ts . “ E .R .A .” = B ritis h E le c tric a l a n d A llie d In d u s tr ie s R e s e a r c h A s s o c ia tio n . “ M .A .” = M e ta llu r g ic a l A b s t r a c ts . “ M .R . ” = M a th e m a tic a l R e v ie w s . “ M .-V .” = M c tr o p o lita n -V ic k e r s E l e c tric a l C o ., L t d . “ P .O .” = P o s t O ffice E n g in e e r in g D e p a r tm e n t. “ R .E . A .” = R a ilw a y E n g in e e rin g A b s t r a c ts . ’
512.34 D E C E M B E R 1946 M A T H E M A T IC S 51
ip»
y / 523.755
512.34 : 518.5 3040
Som e num erical m ethods for locating roots o f polynomials. Fry, T. C . Quart. Appl. M ath., 3, 89-105 {July, 1945).— A th o ro u g h discussion is given o f tw o g ro u p s o f m ethods. T h e first involves m atrix iteratio n , a n d th e m eth o d s o f A itk en a n d B ernoulli a n d v a ria tio n s o f these com e w ithin this category.
T h e second g ro u p depends o n C au ch y ’s th eo rem regarding th e n u m b er o f ro o ts w ithin a closed c o n to u r in th e com plex plane. I n o n e m eth o d the n u m b e r o f ro o ts w ith real p a rts g re a te r th a n a given value is fo u n d . R e p etitio n o f th e process segregates the ro o ts w ithin strip s parallel to th e im aginary axis. T h en by a ro u tin e process th e values o f th e real p a rts o f the ro o ts m ay b e fo u n d ; an d , using these, th e im aginary p a rts a re determ in ed a t once. A m achine, called the Iso g ra p h , is also described fo r d eterm in in g the ro o ts.
T h is gives accuracies to a b o u t 1% a n d th e quickest m eth o d is to use this m achine first and th en im prove
th e values, if necessary, b y o n e o f th e m eth o d s
described in the paper. l. s. g.
5 1 8 .1 :6 2 1 .3 1 7 .3 9 3041
C om putation problem s in circuit design. Baker, G . T. P .O . Elect. Engrs' J „ 39, 58-63 {July, 1946).—
A nalyses c ertain co m p u ta tio n processes a n d re p ro duces these in physical term s, using telephone type a p p a ra tu s . T h e technique is illu strated by a n ap p lic a tio n to tim e m easu rem en t problem s.
518.5 : 512.34 see Abstr. 3040
518.5 : 621.317.39 3042
A twelve equation com puting instrum ent. Berry, C . E ., and Pemberton, J. C . Instruments, 19, P t I, 396-8 {July, 1946).— [A bstr. 2849 B (1946)].
519.241.6 3043
R epresentation o f relative variability on a sem i- logarithm ic grid. Muhsam, H . V. Nature, Land., 158, 453 {Sept. 28, 1946).
A S T R O N O M Y . G E O D E S Y 52
5 2 2 .6 1 7 .2 :5 2 3 .8 2 1 .3 3044
The F ab ry m ethod o f stella r photom etry. Redman, R . O . M on. N ot. R. A str. Soc., 105 {N o. 4) 212-24 (1945).— E x p e rie n c e 'a t P re to ria in the use fo r p h o to m etry o f th e im age o f th e telescope objective form ed in th e light o f a selected o bject by a n auxiliary sh o rt- focus lens n e a r th e focal p lan e is described. A n acc u rate light c u rv e o f R S S g tr o b tain e d by this m eans show s a n av erag e dev iatio n fo r o n e ex p o su re o f 0-013 m ag. C o n tin u o u s reco rd in g o n a m oving em ulsion im proves th e p h o to m e tric accuracy only o n nights w ith a p o o r sky. R esu lts o b ta in e d in checking a m ag n itu d e sequence a re c o m p a red w ith fo u r in d ep en d en t sets o f m agnitudes. T h e F a b ry m ag n i
tu d es sh o w th e sm allest average dev ia tio n fro m the
m ean. " a. hu.
522.617.2 : 523.821.3 see A bstr. 3055 522.982.2 : 535.313.6 see A bstr. 3111
5 2 3 .1 1 2 :5 3 0 .1 2 3045
T heoretical cosm ology. Walker, A . G . O b
servatory, 66, 285-9 {June, 1946).— A n exp an d in g m odel universe is con sid ered in w hich th e frequency o f every a b so rp tio n line, m easu re d a t th e source, is c o n sta n t in th e /-tim e o f generalized kinem atical relativity, a n d th e ra te a t w hich q u a n ta o f an y p a r
tic u lar w ave-frequency a re em itted fro m a neb u la oc 1/t, w here / is m easu red fro m th e in stan t w hen th e u niverse sta rte d to ex p an d . In th e eq u iv alen t static m o d el th e w ave-frequency oc t a n d th e em ission- frequency is c o n stan t. B o th m odels a re co n sisten t a n d agree w ith th e o b serv atio n al co rre latio n s. T he a rg u m e n t is a d a p te d to general relativity by using th e a p p ro p ria te form s o f th e assu m p tio n s. T h e o bserv ed c o rrelatio n s m u st be tak e n to th ird a p p ro x i
m atio n s b efore we c a n distin g u ish b etw een the theories.
A. HU.
523.2 : 536.422.15 see A bstr. 3144 v o l . XLix.—a.— 1946. D e c e m b e r .
523.531 3046
D erivation o f m eteor stream rad ian ts by radio reflexion m ethods. Hey, J. S., and Stewart, G. S.
N ature, Lond., 158, 481—2 {O ct. 5, 1946).—S c a tte r echoes observed o n w avelengths o f 4 -5 m a t 150 kW p e ak pow er, using a directive aerial, w ere fo u n d to be c o rrelated w ith p assage o f m eteors. By inclining the a erial system o n different bearings, th e ra d ia n t d irectio n s co u ld also be determ ined.
523.73 : 523.774 see A bstr. 3050 523.73 : 523.775.2 see A bstr. 3052
523.746 3047
A pparent visible violet radiation in the recen t large sunspot group. Bartlett, J: C ., J r . Science, 104, 681-2 {June 7, 1946).
523.752 3048
S o lar prom inences. Bruce, C. E. R . O bservatory, 66, 263—4 {April, 1946).— T h e form , velocity o f p ro p a g atio n , recu rren ce a n d m u tu a l a ttra c tio n o f s o la r pro m in en ces suggest th a t they a re electrical discharges. T h e m ech an ism o f lea d er a n d re tu rn stro k e s is trac ed in c o ro n a l a n d su rg e p ro m in en ces.
S u n sp o ts a re reg ard ed as regions in w hich th e d is
charges a rc extinguished ow ing to th e deflection o f c u rre n t in to a n eig h b o u rin g facula. a. hu.
523.755 3049
P relim in ary results from m easurem ents o f p o lariza
tion in the corona. Ohman.Y . O bservatory, 66 ,2 6 1 -2 {April, 1946).— P o la rig ra p h m easures a t th e eclipse o f Ju ly 9, 1945, sh o w th a t in th e in n er c o ro n a th e per
cen tag e p o lariza tio n agrees w ith th a t expected fro m T h o m s o n scatterin g by free electrons. In the o u te r c o ro n a th e p o lariza tio n is co n sid erab ly less a t all w avelengths, in d icatin g the presence o f a n a d d itio n al lig h t-sc atterin g process p ro d u c in g a su p e rp o sed ra d ia tio n , practically u n p o larized . T h is is p ro -
335 12
visionaliy identified w ith the F ra u n h o fe r spectrum arising fro m G ro tria n particles. a . h u .
523.774 : 523.73 3050
New m easures o f the sodium line D j in the solar spectrum . E v e r s h e d , J . M on. N ot. R. A str. Soc., 105 {No. 4) 200 3 (1945).— S udden changes a t b o th cen tre a n d lim b in th e shift to w a rd s red o f th e so lar line D , c o m p ared w ith v acu u m -tu b e em ission are a ttrib u te d to D o p p le r effects o f m o tio n in the N a gas.
T h e m ean v alu e o f th e shift a t th e c en tre is slightly in excess o f the relativity value, possibly d u e to a general descent o f N a . T h e excess is still larg er a t th e lim b.
T h e to tal shift betw een E. a n d W . lim bs gives a ro ta tio n velocity at a h ig h level in the reversing layer w hich confirm s th a t th e a n g u la r speed increases w ith height in the a tm o sp h ere. a . h u .
523.775.2 3051
Spcctrographic observations o f the so lar Hare o f J u ly 25, 1946. E l l i s o n , M . A . Nature, Load., 158, 450 (Sept. 28, 1946).
523.775.2 : 523.73 3052
T he solar rotatio n and shift tow ards red m easured in prom inence spectra. E v e r s h e d , J . M on. N ot. R.
A str. Sue., 105 (No. 4) 204-5 (1945).— Shifts o f the H a n d K lines in p rom inences betw een 1935 and 1939 give a n g u la r speeds o f ro ta tio n g re ater th a n those derived fro m disc spectra o r fro m su n sp o t m o tio n . T h e m ean daily a n g u la r ro tatio n is 16-9° as co m p ared with 14-5° in the reversing layer a t the e q u ato r. T h e ro ta tio n is a b o u t 2 p er day g re ater a t so la r m ax.
th an a t m in. T h e general shift o f th e lines is 0 012 a as co m p ared w ith the relativity value o f 0-008 a .
a. h u.
523.813 3053
S te lla r p arallax es determ ined photographically at the Cape O bservatory (15th list). M on. N ot. R. A str.
Soc., 105 (N o. 4) 246 52 (1945).
523.813 3054
The selection o f sta rs fo r p arallax observations.
J a c k s o n , J . O bservatory, 6 6 , 318-21 (Aug., 1946).—
T h e c h a ra c te r o f p arallax p ro g ram m es has changed fro m o b serv atio n o f the b right sta rs to o b serv atio n o f those w ith large p ro p e r m o tio n s. T h e ob serv er is w arn ed th a t a selection o f sta rs w ith larg e p ro p e r m o tio n s fro m a g ro u p fo r w hich sm all p ro p e r m o tio n is p ro b a b le will include m an y fo r w hich th e a ctu al e r ro r co n sid erab ly exceeds the p ro b a b le e rro r. F o r such sta rs th e spurio u sly larg e m o tio n is a m isleading index o f p roxim ity o r low lum inosity. D o u b le stars w ith a large dynam ical p a ralla x sh o u ld b e observed
trig o n o m etrically . a . h u .
523.821.3 : 522.617.2 3055
O n th e photom etric use o f plates taken for the determ ination o f stellar paralla x . StoY , R . H ., a n d C o r m a c k , A . M on. N ot. R. A str. Soc., 105 (No. 4) 225- 36 (1945).— A m odified S chilt p h o to m e te r is used to derive p h o to g rap h ic m ag n itu d es w ith a p ro b ab le e rro r o f ± 0 - 0 5 m ag. fo r sta rs in 150 C ape p arallax fields. T h e scale is determ in ed by a ro tatin g sector, a n d th e zero p o in t by co m p ariso n w ith visual m ag nitudes o f 58 sta rs o f k now n sp ectral type. M agnitudes a re given fo r Sirius, C an o p u s a n d K a p te y n 's star.
A . HU.
523.821.3 : 522,617.2 see A bstr. 3044
523.841.1 : 523.877 see A bstr. 3060
523.841.9 = 3 3056
D ark en in g a t the limb in eclipsing binaries. IT.
F e r r a r i , K . S.B. A kad. M s s. M en ., 1 4 8 , Ha (Nos. 3-4) 217-35 (1939) In German.
523.842.2 : 535.422 : 535.317.25 see A bstr. 3112
523.851.2 3057
The structure o f the globular s ta r clusters. F i n l a y - F r e u n d l i c h , E . Mon. N ot. R. A str. Soc., 105 (No. 4) 237-43 (1945).— G lo b u la r clusters a re regarded as settling dow n from a n initial a d ia b atic sta te to a n in ter
m ed iate q u a si-statio n ary sta te con sistin g o f an iso
therm al c o re su rro u n d ed by an a d ia b a tic a tm o sp h ere.
T his h ypothesis explains w hy any observed eliipticity is confined to the core o f b right sta rs a n d w hy th e m o st elliptical cores h av e the shallow est “ a tm o sp h e res”
o f fain t stars. I t suggests a m eth o d o f d eterm in in g the m asses o f clusters fro m th e w id th o f sp ectral lines in the b right cores. P relim inary e stim ates fro m p ro p e r m o tio n s suggest m asses o f the o rd e r o f 10s so la r
masses. a . h u .
523.854 3058
A search fo r the nucleus o f our galaxy. B a a d e , W . Publ. A str. Soc. P a d /., 58, 249-52 (Aug., 1946).—
T h e investigation w as u n d e rta k e n in o rd e r to detect the c en tre o f the galaxy assum ing th a t th e galaxy is a n Sb spiral so th a t its c en tral region sh o u ld consist o f sta rs o f type 11 a n d be rich in clu ster-ty p e variables.
T h e S ag ittariu s s ta r clo u d w as investigated, a ro u n d the g lo b u la r c lu ster N G C 6522, a n d a p relim inary analysis o f the plates reveals a d ensity o f cluster-type variables fa r larg er th a n in o th e r regions o f th e M ilky W ay. T h e distance o f th e S ag ittariu s clo u d estim ated from th e c luster-variables com es o u t a t a b o u t 9 p ar- secs. T h o u g h th e analysis is n o t yet finished, it seems highly p ro b a b le th at the galaxy is a n Sb spiral an d th at its c en tral region is com posed o f sta rs o f type II.
g. c . McV.
523.873 3059
N o te on the H a rv ard and P otsdam system s of spectral classification. B r u c k , H . A. M on. N ot. R.
A str. Soc., 105 (No. 4) 206-11 (1945).— F ro m 5 600 sp ectral types o f sta rs C om m on to th e P o tsd a m S p e k trald u rch m u steru n g - a n d th e D ra p e r a n d Y ale catalo g u es a statistical co m p a riso n is m a d e betw een th e tw o system s. R egressions o f e ac h o n th e o th er a re derived fo r sta rs in tw o m ag n itu d e-g ro u p s. T h e system s a re nearly th e sam e a t AO, K 0 a n d to som e extent GO, w hereas a t F 0 o r 0 5 sy stem atic differences o f 0 -3 class a re found. T h ere is evidence fo r a m ag n itu d e effect an d a difference betw een th e two
P o tsd a m observers. a . h u .
523.877 : 523.841.1 3060
A tom ic possibilities underlying ste llar catastrophe.
J o h n s o n , M . O bservatory, 6 6 ,248-54 (April, 1946).—
T h e degenerate-core th eo ry o f novae is criticized on th e g ro u n d th a t th e physical process o f co llap se is n o t specified, n o k n o w n m o d e o f energy tra n s p o rt carry in g th e p h ase b o u n d a ry th ro u g h th e s ta r fa st e n o u g h fo r the observed su d d en o u tb u rst. T h e n eu tro n -c o re theory o f su p ern o v ae gives n o a cc o u n t o f th e ato m ic re actio n s a ssociated w ith th e p o stu la te d h ig h density o f the n e u tro n ic m a tte r in th e sh ru n k e n co re. A ny successful th eo ry m u st tre a t specifically o f th e re ac tio n 336
529,786
5 3 1 . 2 5 8velocity in siin a n d o f th e tra n s p o rt velocity th ro u g h
the stellar m aterial. a . n u .
529.786:621.396.611.21 ' 3061
A quartz clock. B o o t h , C. F . P .O . Elect. Eitgr.s’ J., 39, 33-7 (July, 1946).— D iscusses th e developm ent o f
the clock a n d its ap p licatio n in astro n o m y . T h e design a n d p erfo rm an ce o f rep resen tativ e u n its are o u tlined. T h e gain o f a typical clock in o n e y e ar in term s o f a n ideal clo ck -o f zero ra te , w ould he 3 -15 sec o v e r a period o f 31 536 000 sec. p. o.
P H Y S IC S 53
53.081.3 3062
O n t h e th e o r y o f s c a le s o f m e a s u r e m e n t.’ S t e v e n s , S. S. Science, 104, 677-80 (June 7, 1946).
F U N D A M E N T A L S 530.1
530.12 = 4 3063
O n c e r t a i n g e n e r a l i z a t i o n s o f c h a n g e o f c o - o r d i n a t e s .
Slansky, S. C.R. Acad. Sci., Paris, 222, 857-8 (A pril 8, 1946) In French.— F o llo w in g u p the w o rk o f D esto u ch es o n L o ren tz tran s fo rm a tio n s in w hich the coefficients m ay include o p e ra to rs as well as o rd in ary num bers, it is show n th at the tran sfo rm a tio n form ulae fo r these o p e rato rs a re deduced fro m the c o -o rd in a te tran sfo rm a tio n fo rm u lae as if su ch o p e ra to rs w ere
o rd in ary num bers. w. e. d.
530.12 : 523.112 see Ahstr. 3045 530.12 : 535.337 see Ahstr. 3115
530.145 3064
O n t h e q u a n tu m t h e o r y o f w a v e fie ld s . Belinfante, F . J. Physlca, \v Grav., 7, 765 -78 (O ct., 1940).— T h e th eo ry o f H eisenberg a n d P a u li is developed a n d th e p r o o f o f the rclativistic invariance o f the c o m m u tatio n rules is treated in a m o re general m an n e r in w hich the cases o f th e electrom agnetic field an d heavy q u a n ta a re considered. F o r sim plicity, only first o rd e r L a- g ran g ian o p e ra to rs a re con sid ered a n d th e im p lications o f this a re discussed. T h is trea tm e n t co nsiders in detail th e F e rm i-D ira c statistics a s well a s th e E in stcin -B o se statistics dealt w ith by H eisenberg and
Pauli. w . E. D.
530.145 3065
N e w d e v e lo p m e n ts in r e la t i v i s t i c q u a n t u m t h e o r y . Mo l l e r, C. Nature, Land., 158, 403-6 (Sept. 21, 1946).— T h e w ell-know n divergence difficulties o f o rd in ary q u a n tu m th eo ry are discussed a n d som e o f th e featu res o f H eisenberg’s new m eth o d [A bstr. 2109 (1944)], th e so-called “ S -M atrix m eth o d ,” a re described. W hen 5 is given, th e asy m p to tic b eh av io u r o f th e w ave fu nctions a n d all kinds o f cross-sections a re d eterm ined. S is a u n ita ry L o rcn tz-in v arian t
m atrix . l. s. g.
530.145 = 3 3066
A p r o b le m o n th e t h e o r y o f 't h e d c u t c r o n . Bleuler, K. Heiv. Phys. A d a ., 17 (No. 6) 405-8 (1944) In German.
5 3 0 .1 4 5 .6 :5 3 6 .4 8 3067
T he lowest wave function o f the sym m etrical m any particles system . Bijl, A . Commutt. K. Onnes Lab., Leiden (Suppl. No. 90). Physica, 's Grav., 7, 869-86 (N ov., 1940).— T h e general schem e o f the p e rtu rb a tio n th eo ry , in w hich th e p e rtu rb a tio n in th e w ave fu n ctio n is developed in a series o f pow ers o f th e p e rtu rb a tio n p a ram ete r, leads to divergent results fo r th e low est sym m etrical w ave fu n ctio n in th e lim iting case o f an infinite n u m b e r o f particles. T his difficulty can b e
avoided by applying a developm ent o f the logarithm o f th e w ave fu n ctio n in pow ers o f th e p e rtu rb a tio n p a ram eter. U sing th e wave fu n c tio n so o b tain e d , it is show n th at in the low est sta te o f a system o f m any in te ractin g p articles no density fluctuations occur.
Som e p ro p erties o f the sp ectru m o f energy levels o f the m any p articles system a rc discussed, a n d a general p r o o f is given o f th e existence o f an “ excitation energy,” w hich is necessary to give one p article a m o tio n relatively to the others. A s a consequence, o n e c o u ld expect th a t th e specific h e a t o f liquid helium I I w ould be expected to increase as exp ( — a IT), a n d n o t w ith som e p o w e r o f T.
530.162 : 537.228.1 : 536.53 see Abstr. 3146
M E C H A N IC S O F SO LTD S 531
531.19 = 3 3068
O n B ose-statistics. S c h u e e r t , G . Z . Naturforsch., 1, 111 20 (M arch, 1946) In German.— G en tile [Nuovo Cjm., 17 (No. 10) (1940)] restricted th e m axim um n u m b e r o f particles allow ed to e ac h available sta te to N , the to ta l n u m b er o f particles in th e assem bly, an d gave co rrectio n term s to the usual form ulae.
It is proved th a t G en tile’s m eth o d a n d th e usual m eth o d o f u n restricted n u m b ers m u st give the sam e exact results fo r th e p a rtitio n fu n ctio n , e ith er by using the sym m etry p ro p erties a n d q u a n tu m m echanics, o r by th e D a rw in -F o w le r m eth o d . In an expansion, th e G en tile term s a re o f o rd e r e~ N , T erm s o f o rd e r (1 /A ) a re explicitly o b tain ed by th e D a rw in -F o w le r m eth o d . N e a r a b so lu te zero no term s c an be o m itted , a n d the m ean o ccu p atio n n u m b ers a n d energy in this region a re fo u n d from the
basic definitions. o . J. k .
5 3 1 .2 2 4 :5 3 1 .7 8 7 3069
E lastic behaviour o f the so-called Bourdon pressure gauge. B i e z e n o , C . B., a n d K o c h , J. J. Proc.
Ned. A kad. W et., 44 (No. 7) 779-86; (No. 8) 914-20 (1941).— A m ath em atical th eo ry o f th e B o u rd o n gauge en ab lin g d efo rm atio n a n d stresses in the B o u r
d o n tu b e to be calcu lated , a n d tak in g in to a cco u n t b o th the flexural stiffness o f th e tu b e wall a n d th e so-called “ flatten in g ”, o f th e tu b e a s described by v on K d rm d n [A bstr. 1 (1912)] is developed. V ery hig h stresses a re p ro d u c ed by relatively low pressures, a n d p ro p o rtio n a lity betw een stress a n d stra in is v iolated a t p ressures fo r w hich th e gauge is said to b e designed. H en ce m an y ru p tu re s o c cu r; elastic
hysteresis is o bserved. J. s. g . t .
531.258 3070
T he elastic stresses produced in a thick plate by the application o f pressure to its free surfaces. S n e d d o n , I. N . Proc. Camb. Phil. S oc., 42, 260-71 (O ct..
1946).— T h e m eth o d o f H a n k el tran s fo rm s in tro d u ced in a prev io u s p a p e r [A bstr. 1739 (1945)] is u se d to 337
531.258
c alcu late th e n o rm al displacem ent o f a p o in t on the free surface o f a sem i-infinite elastic m edium , p a rt o f th e plan e b o u n d a ry o f w hich is deform ed by the pressu re o f a rigid bod y . T erozaw a's so lu tio n o f this p ro b lem is o b tain e d as a special case o f a m ore general theory' w hich is th en applied to th e case w here the elastic m ed iu m is b o u n d ed by 2 p arallel planes a finite distan ce a p a rt, n o rm al pressures being applied to these free surfaces. T h e analysis is la te r sim plified by assu m in g th e applied pressures a re sym m etrical a b o u t a cen tral p lane; this p ro b lem w as tre a te d in 2 d im en
sions by F ilo n a n d th e 3-dim ensional so lu tio n is now
given. h. j. h. s.
531.258 : 539.312 3071
T he clastic response o f a larg e p late to a G aussian distribution o f pressure varying with tim e. Sneddon, I. N . Proc. Camb. Phil. Soc., 42, 338-41 (O ct., 1946).— A prev io u s analysis [A bstr. 657 (1946)] is ex ten d ed to discuss th e v ib ra tio n s o f a thin elastic p late subjected to a sym m etrically disposed G a u ssia n p ressu re d istrib u tio n vary in g w ith tim e.
E xpressions a re derived fo r th e displacem ent an d velocity o f any p o in t o f th e p la te in term s o f the applied p ressu re a n d th e ir a p p lic atio n to the case w hen th e p ressu re is d u e to an im pulse o f very sh o rt d u ra tio n is d em o n strated . h. j. h. s.
531.44 3072
T he influence o f electric potentials upon friction.
I. In aqueous solutions o f salts. Clark, R. E. D . Trans. Faraday Soc., 42, 449-56 (M ay, 1946).— A n investigation is m ad e o f the n a tu re o f th e frictional changes w hich o ccu r a t a n o n -m etal/m e tal interface lu b ricated by an electrolyte, w hen th e m etallic surface is electrified. T h e a p p a ra tu s used is described in P a rt I a n d consists o f a fine tung sten w ire (0-025 m m d ia.) w ra p p ed h a lf ro u n d a ro tatin g P erspex wheel, th e tw o ends o f th e w ire being held in tension by springs a n d ch an g es in th e e q u ilib riu m p o sitio n o f the w ire being caused to m ove a p o in ter. In this m a n n e r it w as fo u n d easy to detect changes in friction w hich m ight persist only fo r a frac tio n o f a second w hile any desired sensitivity co u ld easily b e secured. A p p lica
tio n to th e dep o sitio n o f m etals a t th e ir reversible p o ten tials in dicated a new tec h n iq u e fo r th is study w hich m ay ultim ately be o f v alu e in anaylsis. F ric
tio n a l effects w ith n o n -d ep o sitab le catio n s a re co n sid ered , a n d a discussion o f responses w ith N aC l so lu tio n s is included, follow ed by a d escription o f the effects given by p o la r m olecules, fo r w hich curves a re show n o f th e responses o f a 1-2% so lu tio n o f soft
so a p . H. H. HO.
531.44 3073
T he Influence o f electric potentials upon friction.
I I .'C l a y s : equilibrium responses. Clark, R . E. D . Trans. Faraday Soc., 42, 456-61 (M ay, 1946).—
E x p erim en ts o n clays w ere u n d e rta k en because it w as in dicated o n th eo retical g ro u n d s th a t a suspension c o nsisting o f flat particles sh ould exhibit c h ara c teristic frictional responses w hen in c o n ta c t w ith a su itab le m etal electrode, a n d m ight affo rd a m eth o d fo r th e id entification o f clays. T h e,ex p erim en tal d a ta o b tain e d in dicated th a t, in th e -■ case o f strongly an iso tro p ic p articles suspended in w a ter: (1) A n u p w a rd rise in th e frictio n /v o ltag e curve follow ed by a fall is co n n ected w ith th e p resence o f b alan ce ions on
th e suspended p articles. (2) A n im m ed iate fall in friction is caused by th e o rien tatio n o f particles a t the sliding surface. (3) A su b seq u en t rise— in th e range 2 -4 volts— o n ly o ccurs w hen th e particles a re co n ducting. (4) T h e conductivity o f p articles, a t rig h t angles to th e ir plane, is also responsible fo r the previously described rectification betw een a “ m o v in g ” an d a s ta tio n a ry electrode. h. h. ho.
M E C H A N IC A L M E A S U R E M E N T S 531.7 531.787 : 531.224 see A bstr. 3069
531.787 : 621.182.27 : 536.5 see A bstr. 3145
531.787.9 3074
A n instrum ent fo r determ ining the p a rtial pressure o f oxygen in a gas. Pauling, L ., Wood, R . E ., and Sturdivant, J. H . J. Am er. Chem. Soc., 68, 795-8 (M ay, 1946).— A com p lete d escription, with c alib ra
tio n curves, is given o f a n in stru m e n t previously re p o rte d [A bstr. 1806 (1946)].
M E C H A N IC S O F L IQ U ID S 532
532.13 3075
V iscosity o f glass a s affected by dissolved gases.
Graff, W . A ., and Badger, A . E. Phys. Rev., 70, 220 (Aug. 1 an d 15, 1946).
532.13 3076
Viscosity o f associated liquids. Douglas, R . W . Nature, Load., 158, 415 (Sept. 21, 1946).
532.13 = 3 3077
D eterm ination o f internal friction o f heavy and light m ethane between 322°K and 90°k. van Itterbf.ek, A.
Physica, 's Grav., 7, 831-7 (N ov., 1940) In German.
532.516 3078
R ole of inertia in hydrodynamic lubrication. Shaw, M . C ., and Strang, C . D .; Fogg, A . Nature, Loud., 158, 452 (Sept. 28, 1946).— I t is claim ed th at F o g g ’s e x p lan atio n o f th e o p e ra tio n o f p arallel surface th ru st bearings, o p e ratin g a t high speeds, in term s o f a tem p e ra tu re g rad ie n t in th e oil, a n d con seq u en t th erm al expansion, is n o t q u a n titativ ely a d eq u a te . In e rtia effects in th e oil, negligible a t low speeds, m u st be tak en in to a cco u n t. F ogg, how ever, qu estio n s this in te rp reta tio n a n d m ain tain s th a t in ertia is only a sec o n d -o rd er effect.
532.522 = 4 3 0 7 9 '
T he law of lim iting height relating to the aspiration of tw o fluids of different densities. Gariel, P. C.R.
Acad. Sci., Paris, 222, 781-3 (A pril 1, 1946) In French.
— T h e efflux o f fluid fro m a h o rizo n tal slit in a-vertical w all closing a h o rizo n tal glazed ch an n el c o n tain in g tw o superim p o sed layers o f salt- a n d fresh w a te r is briefly discussed, p a rtic u la r a tte n tio n being p aid to v ariatio n o f th e efflux as th e h eight o f th e interface, (h), above o r below th e slit is changed. T h e lim iting height, he, is defined as th e h eight o f the interface, a bove o r below the slit, w hen th e efflux Q c o n tain s less th an 1% o f salt w ater. T h e experim ental results a cco rd w ith th e th eo retical e q u atio n lie K ( Q \ / p/g/\f>)2tl in w hich p a n d p + A p a re the respective densities o f th e fresh a n d sa lt w ater.
J. s. G . T .
532.542 : 621.181.5 3080
A thermodynamic theory of circulation in water-tube boilers. Silver, R. S. Proc. Instn Mech. Engrs, 338
5 3 2 .6 1 2 .4 .0 9 6 = 4 532.74
Lorn!., 153 ( War Emerg. Issue No. 9) 261-71 (1945).—
[A bstr. 2796 B (1946)].
532.612.4.096 = 4 3081
Law o f variation o f surface tension with tem perature.
Mez g e r, E . C.R. A cad. Sci., Paris, 222, 948-50 (A pril 15, 1946) In French.— T h e su rfa ce tension o f a liq u id is given by th e fo rm u la
Y = UaN i ( l - 0 2)(>d - / ) - 2
H ere U0 = PTC2, w here Tc is the critical tem p eratu re a n d (i a c o n sta n t, N is A v o g a d ro ’s n u m b er, 0 the tem p e ra tu re, v = N r 3 (r being th e ra d iu s o f the m olecule), a n d / is a c o rrectio n facto r.
5 3 2 .7 2 :5 4 1 .6 4 3082
T herm al m igration o f m acrom olecules. Hartley, G . S., a nd Tom s, B. A . N ature, Lond., 158, 451 (Sept. 28, 1946).—O b serv a tio n s confirm ing th e ra p id th erm al diffusion o f p o ly m e r m olecules a re rep o rted . P olym ethyl m e th acry late in 3% so lu tio n in m o n o - c h lo ro b en zen c w as placed in a cell co m p o sed o f tw o plates, 1 cm a p a rt, held a t 115°c a n d 14°c respectively.
In 2 h o u rs, a jelly a d h ere d to th e h o t p late co n tain in g 8 • 8% o f th e polym er. T h e term “ th erm al m ig ra tio n ” is preferred fo r th is ph en o m en o n .
532.74 : 541.127.2 : 541.18 = 3 3083
P ro p erties o f reversible m icelle form ation from the standpoint o f the m ass action law. Lamm, O . A rk.
K emi M in. Geol., 18 A (N o. 2) P aper 9, 22 p p . (1944) In German.— T h e a u th o r defines m icelle fo rm atio n as th e ag g reg atio n o f m olecules o r io n s o f a su b stan ce o f relatively low m o lecu lar w eight, w hen th e c o n c en tratio n o f its so lu tio n is increased. T h e m ath e m atical th eo ry o f sim ple m icelle fo rm atio n is first developed, in cluding th a t o f id eal-inhom ogencous micelles, a n d is follow ed by a discussion o f sed im en ta
tio n a n d diffusion (m em b ran e a n d free) in relatio n to m icelle fo rm atio n o f non-electrolytes. T h e s ta n d p o in t tak en is th a t o f th e m ass-actio n law , w ith the in ten tio n o f th ro w in g light u p o n d e v iatio n s fro m it, a n d , in p articu lar, th e trea tm e n t includes th a t o f p roblem s relatin g to critical c o n ce n tra tio n s fo r m icelle form a
tio n . T h e p a rticle -d istrib u tio n cu rv e o f th e poly- disperse so lu tio n o f a sim ple case o f non -h o m o g en eo u s reversible m icelle fo rm atio n , w hen it c an be a p p ro x i
m ate d to a n ideal G a u ss crro r-cu rv e, rem ain s ideal fo r all co n ce n tra tio n s fo r w hich th e sim ple law s o f so lu tio n h o ld g o o d . h. h. h o. 5 3 2 .7 4 :5 4 1 .1 8 :5 3 5 .3 4 3 .3 2 . 3084 T he determ ination o f critical concentrations for the form ation o f soap m icelles by the spectral behaviour o f pinacyanol chloride. Co r r in, M . L ., Elevens, H . B., a nd Ha rkin s, W . D . J. Chem. P hys., 14, 480-6 (Aug., 1946).— T h e a b so rp tio n spectrum o f p in a c yanol ch lo rid e in a q u eo u s so lu tio n s o f an io n ic so ap s changes sh arp ly to th a t ch aracte ristic o f its so lu tio n s in o rg a n ic solvents o v e r a sh o rt ran g e o f so a p c o n c en tratio n . T h is effect is a ttrib u te d to th e fo rm atio n o f m icelles, in w hose h y d ro carb o n -lik e layers o r cores th e dye is solubilized. T h e critical c o n ce n tra tio n s a n d spectral changes w ere determ ined fo r K. lau ra te a n d m yristate, alk ali oleate a n d d ilinoleate soaps, N a cetyl su lp h a te , K d eh y d ro ab ietate.
532.74 : 541.183 3085
S tru ctu re o f soap micelles indicated by X -rays and the theory o f m olecular orientation. I. Aqueous solutions. Ha rkin s, W . D ., Mattoon, R . W ., and
v ol. xlix.—a.— 1946. December. 339
Co r r in, M . L. J. Amer. Chem. Soc., 68, 220-8 (Feb., 1946).— A lo n g spacing v acu u m X -ray cam era is described. F iltered X -rays p ass th ro u g h a w indow o f p u re B e 0 -0 0 4 in th ick cem ented o n th e cam era cover, th en th ro u g h tw o P b slits, th en th ro u g h th e cell w ith 0-01 in Be w indow s hold in g th e so ap solu tio n , a n d finally register o n th e p h o to g rap h ic film. T he thickness o f so lu tio n exam ined is 1-0 m m . O n the th eo ry o f m o lecu lar o rien tatio n in interfaces, the X -ray diffraction p h o to g rap h s o f n o t to o dilute a q u eo u s so lu tio n s o f so ap s reveal th a t th ere exist d o u b le layers o f so ap m olecules w ith “ w ater” layers betw een them . In th e d o u b le layers th e h y d ro carb o n c hains a re o rien ted to w ard each o th er, w ith the p o lar g ro u p s to w ard th e w ater. I n o rd in a ry so ap s the p o la r g ro u p s co n stitu te a negatively ch arg ed layer w hilst th e w a ter layer c o n ta in s diffuse layers o f positive ions, a n d p resum ably in teractio n o f these ions give a definite thickness, related to th e a m o u n t o f w a ter in th e so a p so lu tio n , to th e w a te r layer.
M icelles a re n o t less th an fo u r d o u b le layers thick.
L ay er spacing, d, o f m icelles c an b e expressed by eith e r d = 21 + k log 1/c o r d — b — ac, w here k , a a n d b are consts. a n d c is th e w eight fractio n o f so ap . O n these a ssu m p tio n s th e a m o u n t o f m icellar w a ter h as been calculated. M icellar layer spacings vary fro m 30 to 100 A, s h o rt spacings are a p p ro x im ately c o n sta n t a t 4 • 5 A fo r c o n cen tra tio n s fro m 4 -5 to 35%, an d , in this d irection, th e stru c tu re is th a t o f a liquid. I n an y g ro u p in w hich th ere is close pack in g th e ch ain -to -ch a in distan ce is 5 -4 A a n d th e a rea p e r m olecule is 2 6 -4 A2. W hen a h y d ro c a rb o n c h ain o f a so ap changes fro m th e sta te in w hich it is entirely se p a ra ted a n d su rro u n d e d by w a ter to the sta te in w hich it is su rro u n d e d by o th e r h y d ro c arb o n c h ain s th e re is a very large decrease in free energy, causing, it is believed, th e ag gregation o f single so ap m olecules in to m icelles a lth o u g h increase in electrical energy associated w ith ionic charges ten d s to dim inish th is aggregation. E q u im o lecu lar so lu tio n s o f p o ta s
sium la u ra te a n d p o tassiu m m y ristate give spacings o f 51-3 a n d 61-5 A. T h e b eh av io u r o f th eir m ixtures, a n d th e effect o f th e a d d itio n o f salts o n th e layer spacing a n d th e in ten sity o f th e X -ray p a tte rn s are
discussed. w . r. a.
5 3 2 .7 4 :5 4 1 .1 8 3 3086
D iffraction o f X -rays by aqueous solutions o f hcxano- laniine oleate. R o ss, S., a nd McBain, J. W . J. Amer.
Chem. Soc., 68, 296 9 (Feb., 1946).— T ran s p are n t system s w ere exam ined over a range o f co n ce n tra tio n fro m 30 to 92% so ap . A ll system s sh o w a h a lo w ith th e B ragg spacing o f 4 - 5 -4 -6 A a n d a long spacing o ften in tw o o rd ers. W hen th e so lu tio n s c o n ta in m o re th a n 40% so ap th e w a te r h a lo e s d o n o t a p p e a r.
T hese results in d icate th e p resence o f lam ellar m icelles in a q u eo u s so lu tio n s o f co llo id al electrolytes a n d th e m icelles c o n sist o f a lte rn a te layers o f so a p a n d w ater giving rise to th e long spacings. T h e system s stu d ied in clu d ed th o se w hich w ere (1) fluid a n d iso tro p ic, (2) fluid a n d a n iso tro p ic , a n d (3) sem i-solid an d a n iso tro p ic. In all th ese system s th e lo n g sp acin g s increase a p p ro x im ate ly linearly. I t a p p ea rs th a t th e essential s tru c tu re o f th e m icelles rem ain s unaffected th ro u g h o u t th e c o n c e n tra tio n ra n g e a n d it is th e c h anging rela tio n s o f th e m icelles to e ac h o th e r th a t cause th e v a ria tio n s in p ro p erties. w . r. a.
12*
533.5 = 4 3087 A safety device for vacuum a p p aratu s. S c h e r e r , M . C.R. Acad. Sci., Paris, 222, 997 (A pril 24, 1946) In French.
5 3 3 .5 6 :6 2 1 .3 8 5 .1 = 4 3088
Evacuation o f emission tubes o f medium and low power. P l i o n , P. L e Vide, 1, 71-8 (M ay, 1946) In French.— [A bstr. 2657 B (1946)].
A C O U S T IC S . V IB R A T IO N S 534
534.13 = 5 3089
T he equivalent circuit o f a spherical vibrator.
Sacerdote, G . A h a Frequenza, 15, 28-33 (M arch, 1946) In Italian.— T h e an alytical expression fo r the specific aco u stic im p ed an ce o f a spherical /¡-order v ib ra to r is derived a n d th e eq u iv alen t electric circuit established.
534.213 3090
T he velocity o f dilatatio n and Rayleigh waves in m etal bars. M c M i l l e n , J. H . J. Acoust. Soc. Amer., 18, 190-9 (July, 1946).— Single elastic waves in rock a n d m etal specim ens, sta rte d by im p act fro m a fast m oving steel sphere, w ere stu d ied by p a rtially im m ersing th e specim en in w a te r a n d o bserving the body w aves in th e w ater by m ean s o f sp a rk sh ad o w gram s. W aves in th e w ater w ere observed to com e fro m th e d ila tatio n b o d y wave a n d th e R ayleigh surface-w ave in th e solid. T h e d ila tatio n w ave velocities w ere m easured using the slope o f th e w ave fro n t in w ater; these agreed well w ith th e velocities calcu lated fro m th e elastic c o n stan ts. T h e velocity o f th e first w ave o r pulse c o rresp o n d ed to th e velocity o f a d ila tatio n w ave in a n infinite m edium , while w ave velocities m easu red w hen th e b a r w as in re so n a n t oscillatio n h a d values c h ara cteristic o f a d ila ta tio n w ave in a n a rro w b ar. T h e m easured R ayleigh su rface w ave velocities show ed g o o d agree
m en t w ith th e th eo ry . S p a rk sh ad o w g ram s w ere also m ade, show ing th a t a R ayleigh w ave is p ro d u c ed w hen a d ila tatio n w ave passes th ro u g h a n interface a t nearly n o rm al incidence. R ayleigh w aves w ere also observed to p ro d u c e a second R ayleigh w ave a t a sq u a re c o rn er, d em o n stra tin g th a t th e R ayleigh w ave h as a co m p o n e n t o f d isplacem ents w hich is parallel to the surface.
534.222.2 3091
A determ ination o f the wave form s and law s o f propagation and dissipation o f ballistic shock waves.
D u M o n d , J. W . M ., C o h e n , E. R ., P a n o f s k y ,
W. K . H., a n d D e e d s , E. J. Acoust. Soc. A m er., 18, 97-118 (July, 1946).— E x perim ents to ascertain the w ave fo rm s an d law s o f p ro p a g atio n a n d dissip atio n o f ballistic shock w aves to large distan ces (80 yd) fro m th e bullet trajec to ry a re described. C alibres 0 -3 0 a n d 0 -5 0 in, 20 a n d 40 m m w ere stu d ied . In every case a n N -sh ap e d w ave profile w as observed co n sisting o f a su d d en rise in pressu re (“ h e ad d is
co n tin u ity ” ) follow ed by a n a p p ro x im ately linear decline to a p ressu re a b o u t equally fa r below a tm o spheric, a n d th en a second su d d en re tu rn (“ tail disco n tin u ity ” ) to atm o sp h e ric pressure. T h e peak am p litu d es o f this d istu rb an ce a rc fo u n d to dim inish ab o u t as th e inverse i pow er o f th e m iss-distance
M E C H A N IC S O F G A SES 533 (p erp en d icu lar d istance fro m th e trajectory) w hile the p erio d T ' (m easured betw een th e d isc o n tin u o u s fronts) increases a b o u t as th e i pow er o f the m iss-distance for calibres 0 -3 0 , 0 -5 0 a n d 20 m m . F o r 40 m m shells the a m p litu d e decays a b o u t as th e inverse 0 -9 pow er o f m iss-distance o v er th e ran g e studied. A theory tak in g a cco u n t o f th e dissip atio n o f th e N -w ave energy in to h eat is developed to explain th e observed behav io u r. A m eth o d o f m easu rin g a b so lu te N -w ave am p litu d es by observing th e ra te o f change o f period T ‘ w ith p ro p a g atio n is described. T h e theory leads to a n a b so lu te relatio n sh ip a t large d istances betw een d istance, a m p litu d e an d p erio d in w hich n o a rb itrary c o n stan ts ap p ear.
534.232 : 534.321.9 see Abstr. 3096
534.24/.25 : 550.341 3092
O n the Stoncley-wave equation. I—II. S c h o l t e , J. G . Proc. N ed. A kad. W et., 45 (No. 1) 20 -5 ; (No. 2) 159-64 (1942).— A p lan e w ave m eets th e plan e surface o f sep a ra tio n o f tw o infinite elastic solids and gives rise to reflected lon g itu d in al a n d transverse waves a n d sim ilar refracted waves. T h e b o u n d ary c o n d itio n s lead to e q u atio n s lin ea r in th e a m plitudes.
W hen the a m p litu d e o f th e incident w ave is e q u ated to zero a d ete rm in an tal eq u atio n , th e Stoneley-w ave e q u atio n , is ob tain ed . T h is e q u atio n is discussed a n d lim its a re o b tain e d fo r th e possible ran g e o f values o f its ro o ts. T h e c o n d itio n (on the m aterial c o n stan ts) is fo u n d in o rd e r th a t Stoneley waves shall be possible a t th e in terface o f th e tw o m edia.
l. s . G .
534.24/.26 3093
Transm ission, reflection, and guiding o f an e x ponential pulse by a steel p late in w ater. II. E xperim ent.
O s b o r n e , M . F . M ., a n d H a r t , S. D . J. Acoust. Soc.
Am er., 18, 170-84 (July, 1946).— In th is p a p e r are given th e results o f a n ex p erim en tal stu d y o f the in teractio n o f a n ex plosion w ave w ith a w ater-b ack ed steel plate. D a ta a re given show ing th e dependence o f th e tran sm itte d a n d reflected w aves o n th e an g le o f incidence, a n d o f th e d iffracted w ave o n p o sitio n b ehind th e plate. T h e p late acts as a filter, rem oving th e h ig h frequencies fro m the tran sm itte d w ave a n d th e low frequencies from th e reflected w ave. T he reflected w ave is ap p ro x im ately c o n sta n t in sh ap e, o r tim e scale, w ith vary in g an g le o f incidence. Its am p litu d e h as a b ro a d m ax im u m a t n o rm a l incidence.
I n a d d itio n to the reflected, tran sm itte d a n d diffracted waves, w aves can travel alo n g the p late, in w hich case the p late acts as a w ave guide. A s a co n seq u en ce o f d ispersion in the g uided waves, a p re c u rso r precedes th e explosion w ave as it travels alo n g th e plate.
T h e dependence o f th e frequency, len g th a n d a m p li
tu d e o f this p re c u rso r u p o n o rien tatio n o f th e plate, p o sitio n a n d tim e h as been determ ined.
534.321.3 3094
A ju st scale fo r music. J o n e s , A . T . J. Acoust.
Soc. A m er., 18, 167-9 (July, 1946).
534.321.6 : 534.845.2 3095
T he absorption o f ultrasonic waves in benzene.
Q u i n n , J. J. Acoust. Soc. Am er., 18, 185-9 (July, 1946).— T h e a b so rp tio n w as m easured as a fu n ctio n o f th e tem p e ra tu re by m ea n s o f th e sonic in ter
ferom eter. T h e frequency-free coefficient varies fro m 0 - 6 6 x l 0 ~ 14 to 0 ' 8 5 x l 0 -14 o v er th e tem p e ra tu re 340
534.321.9 534.845.2
range fro m 7 - 2°c to 73-5°c. It a p p e a rs th a t the a b so rp tio n o f u ltraso n ic w aves in liquids is effected by tw o causes, viz. th e viscosity effect deduced by S tokes, a n d a second effect o f u n c ertain origin. In benzene, th e second effect p red o m in ates o v er
w helm ingly a n d determ ines th e over-all tem p eratu re dependence o f th e a b so rp tio n coefficient.
5 3 4 .3 2 1 .9 :5 3 4 .2 3 2 3096
Refinem ents in supersonic reilectoscopy. Polarized sound. F i r e s t o n e , F . A ., a n d F r e d e r i c k , J. R.
J. Acoust. Soc. A m er., 18, 200-11 {July, 1946).—
O n e fo rm o f sim ple c irc u it fo r the g en era tio n o f the sh o rt d u ra tio n h.f. vo ltag e tra in s used in th e supersonic reflectoscope is show n. T h e req u ire d b a n d w id th o f th e system , including the crystal, is discussed.
T ech n iq u es fo r th e ra d ia tio n o f long itu d in al, shear an d R ayleigh w aves a re set fo rth . E ith e r lo n g itudinal o r sh ear w aves can be used to e stab lish v ario u s m odes o f thickness reso n an ce th ro u g h a p late fo r m easuring velocity o f p ro p a g a tio n o r thickness. S hear waves have so m e o f th e p ro p e rties o f polarized light, fo r instance, d o u b le refractio n has been m easu red by three m eth o d s in elastically a e o lo tro p ic solids a n d a tech n iq u e developed fo r th e d irect in d icatio n o f the a m o u n t o f clastic aeo lo tro p y . By m eans o f a q u a rte r- w ave p late, circu larly p o larize d so u n d can be p ro d u c ed .
5 3 4 .3 2 1 .9 :5 3 5 .4 2 3097
D iffraction o f light by ultra-sonic waves o f very high frequencies. B h a g a v a n t a m , S., a n d R a o , B . R . Nature, Loud., 158, 484 (O ct. 5, 1946).— A 2 m m to u rm a lin e p late w ith fu n d a m e n ta l a b o u t 2 M c/s w as m ad e to oscillate a t all h a rm o n ics u p to the 54th, a n d d iffraction p a tte rn s fro m s ta tio n a ry waves m ain tain ed in a co lu m n o f w a te r w ere observed a t alm o st all frequencies betw een 2 a n d 100 M c/s.
T h e re w as fo u n d to be no d ispersion in distilled w ater betw een 9- 5 a n d 92-3 M c/s.
534.321.9 : 541.127 see A bstr. 3217
534.44 : 534.781 3098
T he p o rtray al o f visible speech. S t e i n b e r g , J. C ., a n d F r e n c h , N . R . J. Acoust. Soc. A m er., 18, 4-18 (July, 1946).— T h is p a p e r discusses th e objectives an d req u irem en ts in th e p o rtra y a l o f visible p a tte rn s o f speech fro m th e view point o f th e ir effects o n th e legibility o f th e p a tte rn s. T h e p o rtra y a l involves a n intcnsity-frequency-tim e analysis o f speech a n d the d isplay o f th e results o f th e a nalysis to th e eye.
Pro ced u res fo r accom plishing th is a re discussed in re la tio n to in fo rm a tio n o n th e read in g o f p rin t a n d o n the ch ara cteristics o f speech a n d its in te rp reta tio n by th e ear. A lso m eth o d s o f evalu atin g the legibility o f the visible p a tte rn s a re described.
534.442 : 534.781 3099
V isible speech c a t h o d e - r a y t r a n s l a t o r . R i e s z , R . R ., a n d S c h o t t , L. J. Acoust. Soc. A m er., 18, 50-61 (July, 1946).— S peech analysis p a tte rn s are m ad e visible o n a special c .r.t., w hose persistent- p h o sp h o r screen is a cylindrical b a n d coaxial w ith the electro n gun. T h e beam is b en t th ro u g h 90° by a m agnetic field an d m oves only in a fixed vertical plane, w hile th e c .r.t. ro tates slow ly a b o u t its axis, so th a t th e p a tte rn s a re visible fo r a second o r m ore. T h e u p p e r p o rtio n o f the screen show s a sp e ctru m analysis up to 3 500 c/s m ad e by m echanically scanning
12 c o n tig u o u s b an d -p ass filters. T h e w id th o f a b an d in th e lo w er p o rtio n o f th e screen is c o n tro lled by th e in stan tan eo u s fu n d am en tal frequency o f the speech.
T h e tra n s la to r h as been used in a train in g p ro g ram m e to stu d y the readability o f visible speech patterns.
534.442 : 534.781 3100
Visible speech tran slato rs with ex tern al phosphors.
D u d l e y , H ., a n d G n i e n z , O . O ., J r . J. Acoust.
Soc. A m er., 18, 62-73 (July, 1946).— E xperim ental a p p a ra tu s is described in w hich th e p h o sp h o r is m o u n ted o n a m oving belt o r d ru m . E x citatio n is accom plished by a row o f up to 16 sm all electric lam ps at rig h t angles to the directio n o f m o tio n o f the belt, each c o n tro lled by a b an d -p ass filter o f a b o u t 300 c/s w idth. T h e p a tte rn s a re visible fo r a b o u t l j s e c an d a re q uenched by red lam ps w hen they pass o u t o f sight. D etails a re given o f th e sm all
“ grain -o f-w h eat" lam ps a n d o f th e electrical circuits em ployed.
534.62 3101
The design and construction o f anechoic sound cham bers. B e r a n e k , L. L., a n d S l e e p e r , H . P ., J r . J. Acoust. Soc. Am er., 18, 140-50 (July, 1946).—
D a ta o n th e p erfo rm an ce o f five different types o f stru ctu res fo r use in echo-free (anechoic) c ham bers a rc presented. T h e best is shaped like a wedge an d m an u factu red fro m glass fibres h eld to g eth er b y a bin d in g agent. W hen m o u n te d in th e ro o m , the wedges a re spaced o u t several inches fro m th e w alls, a n d th e d ih ed rals o f a d jacen t u n its a re tu rn e d th ro u g h 90°. G eneralized specifications fo r th e o p tim a l design o f stru c tu re s a re p resented in term s o f eith er (a) low est frequency a t w hich > 9 9 % a b so rp tio n is desired o r (6) m axim um d ep th o f trea tm e n t w hich m ay be installed in th e ro o m . T h e ap p licatio n o f these specifications to tw o re ctan g u la r ro o m s is show n an d inverse sq u a re law m easurem ents p erfo rm ed in the tw o co m p leted c h am b ers a re presented. In the larg er ch am b er th e d eviations a re w ithin ± 0 - 3 db o u t to 10 ft a n d ± 1 • 0 d b o u t to 30 ft fro m a p o in t source o f so u n d . I n the sm aller, the d eviations a re w ithin
± 1 '0 d b o u t to 10 ft.
534.781 : 534.44 see A bstr. 3098 534.781 : 534.442 see A bstr. 3099
534.844.3 3102
Fluctuation phenomena in room acoustics. M a a , D .-Y . J. Acoust. Soc. A m er., 18, 134-9 (July, 1946):
— T w o types o f flu ctu atio n p h e n o m e n a a re discussed theoretically, utilizing th e c o n cep t o f n o rm al m odes o f aerial v ib ra tio n in th e ro o m . T h e flu ctu atio n noise d u e to th e ra n d o m m o tio n o f a ir m olecules is fo u n d to be a p ro p e rty o f a ir a lo n e a n d in d ep en d en t o f the room . O n th e o th e r h a n d , th e flu ctu atio n d u rin g re v erb eratio n dep en d s o n b o th th e ro o m d im ensions a n d its rev erb eratio n characteristics. P ractical fo r
m ulae o f th e m ag n itu d es o f th e flu ctu atio n s a re presen ted , w hich a re in g o o d ag reem en t w ith p rev io u s ex p erim en tal d a ta . T h e ab ility o f th e blind to e stim ate ro o m size w ith su rp risin g accu racy is e x p lain ed , a n d fu rth e r investig atio n s o n th e p ro b lem o f ro o m liveness as related to flu ctu a tio n p h e n o m e n a as well as its effect o n th e a co u stical design o f a ro o m a re suggested.
534.845.2 : 534.321.6 see A bstr. 3095
