AN ELECTRICALLY CONTROLLED CONSTANT TEMPERA
TU R E WATER BATH FOR THE IMMERSION REFRACTO METER.
B y H . C. Go r e.
The w ater bath of the immersion refractom eter m ust be held w ithin narrow limits a t 17.5° C.— 0 tem perature usually below th at of the room. I t is therefore cooled b y the addition of cold water. A d m itting tap w ater or ice w ater a t a constant rate is unsatisfactory, as constant adjustm ent is required b y changes in room temperature. The device herein described, b y which w ater is added to the bath auto
m atically, has given satisfaction during a period of
m any months. No claim to originality can be made, in view of the m any devices of this kind which have been proposed.
The tap w ater runs through the sight tube A (Fig.
1) and is diverted to the bath when the rubber tube B is closed b y the lever of the sounder C. In warm w eather the w ater is cooled by.p assin g it through the copper coil D, immersed in ice w ater in the vessel E.
The refractom eter bath F is provided with an over
flow pipe, K , and is stirred b y a current of air entering through a tube not shown; E and F are insulated by m agnesia packing to prevent the condensation of moisture which occurs during warm humid weather.
Fig. 1.
T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y .
The thermostat G consists of a long glass tube bent into a flat rectangular coil and fastened to a per
f o r a t e d brass plate resting on short legs on the bottom
of the bath. It is filled w ith m ercury and closed at one end. To the open end is sealed a device shown in detail in Fig. 2. Electric connection is made with the mercury in the therm ostat through the platinum wire A (Fig- 2) which passes
through the glass wall near the double seal. The low tension cur
rent which is made and broken in
th e thermostat at B which operates
the relay R (Fig. 1) is taken as a shunt from the n o - v o lt direct- lighting current b y connecting the ow-tension across adjacent taps on the i,ooo-ohm resistance coil H.
There are seven such taps along the coil and the potential difference between two adjacent ones is about 14 volts when the coil is in the 110- volt circuit. The current which actuates the sounder is made and broken by the relay. I t passes from the relay through the 32-candle power lamp I, then through the electromagnets of the sounder, and back to the line, using the 1 xo-volt direct current. The sounder is of the usual form, rated a t 5-ohms, and
heats but very slightly when the Fig. 2.
current passes through continuously. E xcep t for the simple device shown for supporting the rubber tube, no other change in the sounder is necessary excep t that, if desired, the edges of the lever m ay be beveled so that the rubber tube is closed more easily. Sm all condensers, not shown, situated in the bases of the sounder and relay are used in lessening sparking when the currents are opened and closed in the therm ostat and the relay respectively.
If cooling w ater is added a t a rate ve ry slightly more rapid than is necessary, the tem perature is con
trolled with great exactness. Under these conditions, however, not enough cool w ater would be supplied should the room tem perature rise considerably. On the other hand, if cold w ater is added too rapidly the bath becomes much undercooled a t each addition.
It has been found well so to regulate the supply th at water is added to the bath about half the time. The temperature is then controlled within 0.1 0 C., irrespect
ive of changes in room tem perature.
AS APPARATUS FOR CONTINUOUS SAMPLING OF CON
DENSER WATERS FROM EVAPORATORS.
B y Ge o r g e P. Me a d e. R eceived M ay 16. 1911.
Mr. R. S. Norris, in his article on “ The Determ ina
tion of Sugar Lost b y Entrainm ent from E v a p o rato rs”
T h is J o u r n a l , October, 1 9 1 0 , gives the following
®ethod of sampling condenser waters. ‘‘ F ive liters of condenser w ater are collected, a liter a t a time, at
507 intervals of half an hour, as it leaves the condenser and as near to it as possible.”
This method of interm ittent sam pling is the one usually em ployed. It will give a fairly satisfactory sample where entrainm ent in m ultiple effects is being studied. H owever, in the case of vacuum pans, in which the qu antity and the viscosity of the boiling m aterial are constantly changing, such a sample m ay fail to be representative.
The w riter has devised an apparatus b y means of which a sample m ay be taken continuously throughout any convenient period. It has been vised successfully for two years. The accom panying print shows the arrangement.
“ A ” is the leg pipe of the condenser of the evapora
tor. “ B ” is a quarter-inch pipe entering the leg pipe near the top. “ C ” is a second quarter-inch pipe entering at any convenient point below the lowest level a t which the w ater column in the leg pipe will stand when the evaporator is in use. These quarter- inch pipes project into the leg pipe about tw o inches.
This prevents rust and dirt from the sides of the con
denser from washing into the sample. “ D ” and
“ E ” are h eavy glass carboys. T h e y are connected as shown in the small drawing. A ll connections m ust be air-tight.
; W hen the valves on “ B ” and “ C ” are opened the sampling apparatus becomes a p art of the vacuum system . The condenser w ater is forced through
“ C ” into the carboy “ D ” b y the pressure of the column of w ater in the leg pipe above “ C .”
B y m anipulating the valves the w ater m ay be made to flow into “ D ” in a full stream or drop b y drop as de
sired. “ E ” serves as a trap to catch an y w ater from the upper pipe when the vacuum is broken.
S°8
w ith glycerin and the determ ination can be made irrespective of whether the glycerin a t the beginning of the operation is above or below the temperature at which the determ ination is to be made.
This i found to be much better than placing a rubber tube over the capillary glass tube, as is sometimes T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . July, i9„
The sample w ill stop running when the vacuum is broken b u t it w ill start again when the vacuum is sufficient to lift the column of w ater in the leg pipe above the level of “ C .”
Preparatory to taking a sample the rubber connec
tion between “ C ” and “ D ” should be broken and the end of “ C ” immersed in a little clean water. The valve is then opened. The w ater will be drawn through the pipe and will clear it of rust and d irty water.
The carboys used must be carefully selected. There is danger of a serious accident if th ey are not suffi
cien tly h eavy to w ithstand the atm ospheric pressure.
A s a precaution th ey should alw ays be covered w ith bagging when in connection with the vacuum system.
C u b a n A m e r i c a n S u g a r Co., Ne w Yo r k a n d Cu b a.
AN IMPROVED PICNOMETER FOR GLYCERIN.
B y L. W . B o s a r t , J r . R eceived A pril 27, 1911.
The picnom eter used is of cylindrical form, w ith therm om eter ground in central neck, and with fused- in capillary tube at side.
The Geissler form w ith ground-in capillary m ay also be used if preferred.
The cap which fits on the capillary tube as usually provided has no opening a t the upper end and it is found expedient to attach a rubber tube to the lower opening of the cap, and hold the upper end in the sm all tip of a blast-lam p flame, while blow ing through the rubber tube until a ve ry small hole is blown through the glass.
B y means of this hole, the air can escape when the glycerin expands and enters the cap and will not run down the sides of the capillary tube. A fter the cap has been placed on the apparatus, the picnom eter m ay stand and be weighed at any convenient time.
The im provement on the usual form of picnometer consists of a small cylindrical shaped funnel, 38 m illimeters total length, and 15 m illimeters outside diameter. This is ground to fit the capillary tube.
W hen the glycerin is poured into the picnometer, this funnel is placed on the capillary tube and filled
done, as it is easier to see if the funnel is perfectly clean. It also allows for greater contraction of the glycerin and gives opportunity for better observations.
A cover made from the closed end of a test tube m ay be placed over the funnel to prevent any water being splashed in while the apparatus is in the bath.
Funnels of this description are made fo r ' us by Eim er & Am end, to fit the picnometers we had in use.
La b o r a t o r y o f t h e Pr o c t o r a n d Ga m b l e Ma n u f a c t u r i n g Co.
Ne w Yo r k Ci t y.
ADDRESSES.
FACTORY SANITATION AND EFFICIENCY.1
B y C. E .-A . W i n s l o w , A ssociate Professor of B iology, College of th e C ity of New Y o rk a n d C u rato r of P u b lic H e alth , A m erican M useum of N a tu ra l H isto ry , N ew Y ork.
I t m ay fairly be m aintained that in most industries the largest elem ent invested is w hat m ay be called life capital. For example, in the cotton industry in 1905 there was invested a capital of 613 million dollars while the pay-roll amounted to 96 million a year.
Capitalized at 5 per cent., this pay-roll w ould corre
spond to an investm ent of 1920 million dollars in the form of the hands and brains of the workers. The
1 P rese n ted before th e Congress of Technology. M assachusetts In s titu te of Technology, B o sto n , A pril 11, 1911.
calculation is perhaps a fanciful one; but it illustrates the fundam ental fa ct th at the human element in industry is of large practical im portance.
Once th é operative is trained and at work i t is generally assumed th at the results obtained will d e
pend only on his intrinsic qualities of intelligence and skill. The effect of the environm ent upon him is com m only ignored, but its practical importance is ve ry great. In industries where it has been shown th a t the machine which makes a given fabric requires certain conditions of tem perature and moisture for its successful operation these conditions are m a i n t a i n e d
w ith exem plary care. In every factory, however,
there is another type of machine, the living machine, which is extraordinarily responsive to slight changes in the conditions which surround it. These condi
tions, in this relation, we h abitu ally neglect.
I am not dealing now w ith the sociological and humanitarian aspects of the case. I am quite frankly and coldly, for the moment, treating the operative as a factor in production whose efficiency should be raised to the highest pitch, for his own sake, for th at of his employer and for the welfare of the com m unity at large.
The intimate relation between the conditions which surround the living machine and its efficiency is m atter of common experience w ith us all. Contrast your feeling and your effectiveness on a close, hot, m uggy day in August and on a cool, brisk, bright October morning. Many a factory operative is kep t a t the August level b y an A ugust atm osphere all through the winter months. He works listlessly, he half accom plishes his task, he breaks and w astes the property and the material entrusted to his care. If he works by the day the loss to the em ployer is direct; if he works by the piece the burden of interest on extra machinery has ju st as tru ly to be borne. A t the dose of the day the operative passes from an over
crowded, overheated workroom into the chill night air. His vitality lowered b y the atmosphere in which he has lived, he falls a prey to minor illness, cold and grip and the disturbing effect of absences is added to inefficiency. B ack of it all lurks tuberculosis, the great social and industrial disease which lays its h eavy death tax upon the whole com m unity after the in
dustry has borne its more direct p en alty of subnormal vitality and actual illness.
The remedy for all this is not sim ply ventilation in the ordinary sense in which we have come to under
stand the term. Mr. R. W . Gilbert, of the M assachu
setts Institute of Technology, begins a suggestive paper on "T h e Economics of F a cto ry V e n tila tio n ” in
| The Engineering Magazine for December last as fol
lows: "W ebster’s definition of the w ord ventilation is 'to air’ or ‘ to replace foul air b y fresh.’ In actual practice, however, ventilation should mean more than this. I t should mean the conditioning of the air of any enclosed space to the best require
ments of the occupants of th at space.” Condition
ing of the air so th at the hum an machine m ay w ork under the most favorable conditions— this is one of the chief elements of industrial efficiency as it is of individual health and happiness.
The chief factors in a i r conditioning for the living machine, the factors which in most cases far outweigh all others put together, are the tem perature and humidity of the air. In m any a plant m oney has been spent for an elaborate system of ventilation and if the air has been too hot or too dry or too m oist the effect on comfort and efficiency has been worse than nil.
It is a curious instance of the w ay in which we neglect the obvious practical things and attend to remote and theoretical ones, th at for years more attention has been bestowed on the testing of air for carbon dioxide
■which was supposed to indicate some m ysterious T H E J O U R N A L O F I N D U S T R I A L
danger than on the actual concrete effect of over
heating. H eat, and particularly heat com bined w ith excessive hum idity, is the one condition in air th at has been proved beyond a doubt to be universally a cause of discomfort, inefficiency and disease. Flugge and his pupils in G erm any and Haldane in E n glan d1 have shown th at when the tem perature rises to 80 ° w ith m oderate hum idity or much above 700 with high hum idity, depression, headache, dizziness and the other sym ptom s associated with b adly ventilated rooms begin to m anifest themselves. A t 78° w ith saturated air Haldane found th at the tem perature of the body itself began to rise. The wonderful heat-regulating mechanism which enables us to adjust ourselves to our environm ent had broken down and an actual state of fever had set in. Overheating and excess of moisture is the ve ry worst condition existing in the atmosphere and the v e ry commonest.
T he im portance of the chem ical impurities in the air has dwindled rapidly w ith the investigation of recent years. The common index of vitiation due either to human beings or to lighting and heating appliances is carbon dioxide; but carbon dioxide in itself has no harm ful effects in tenfold the concentra
tion it ever reaches in ordinary factory air. Nor is there any reduction of oxygen which has any physiolog
ical significance. In the B lack Hole of C alcutta and below the battened down hatches of the ship London
derry there was actual suffocation due to oxygen starvation; b u t this can never occur under normal conditions of habitation. I t was long believed th at the carbon dioxide was an index of some subtle and mysterious ‘ ‘ crowd poison” or ‘‘ morbific m atter.
A ll attem pts to prove the existence of such poisons have incontinently failed. There are ve ry perceptible odors in an ill-ventilated room, due to decomposing organic m atter on the bodies, in the mouths, and on the clothes of the occupants. These odors m ay exert an unfavorable psychical effect upon the sensitively organized b u t as a rule th ey are not noticed b y those in the room b u t b y those who enter it from a fresher atmosphere. Careful laboratory experim ents have quite failed to dem onstrate an y unfavorable effects from rebreathed air if the surrounding tem perature is kep t a t a proper level. In exhaustive experim ent b y Benedict and M ilner,’ 17 different subjects were kep t for periods varyin g from three hours to thirteen days in a small cham ber w ith a cap acity of 197.6 cubic feet in which the air was changed only slow ly while the tem perature was kept down from outside.
The am ount of carbon dioxide was usually over 35 parts (or eight to nine times the normal) and during the day when the subject was active it was over 100 parts and a t one tim e it reached 231 parts. Y e t there was no perceptible injurious effect.
The main point in air conditioning is then the maintenance of a low tem perature and of a hum idity not too excessive. For m axim um efficiency the tem perature should never pass 70 0 F. and the hum idity
1 T h e lite ra tu re on this su b jec t is well su m m arized w ith reference to original sources b y T . R . C row der in “ A S tu d y of th e V e n tila tio n of Sleep- in g C ars.’* Archives o f Internal M edicine. 7, 85.
" B u ll. 136. Office of E xp erim en t S ta tio n , U . S . D ept, of Agriculture.
A N D E N G I N E E R I N G C H E M I S T R Y . s ° 9
5io T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . July, i9„
should not be above 70 per cent, of saturation. A t the same tim e a too low hum idity should also be avoided. W e have little ex a ct inform ation upon this point bu t it is a m atter of common knowledge w ith m any persons th at ve ry dry air, especially a t 70° or over, is excessively stim ulating and produces nervous
ness and discomfort. It would prob ably be desirable to keep the relative hum idity between 60 and 70 per cent.
A nother point which m ay be emphasized in the light of current opinion is the im portance of “ per
flation ” or the flushing out of a room a t intervals, with vigorous drafts of fresh cool air. W here there are no air currents the hot, moist vitiated air from the body clings round us like an aerial blanket, as Professor Sedw ick calls it, and such of us is surrounded b y a zone of concentrated discomfort. The delightful sensation of walking or riding against a wind is largely perhaps due to the dispersion of this foul envelope and it is im portant th at a fresh blast of air should sometimes blow over the body to produce a similar effect. The same process w ill scatter the odors which have been noted as unpleasant and to some persons potentially injurious. The principal value of the carbon dioxide test to-day lies in the fact th at under ordinary conditions high carbon dioxide indicates th at there are no air currents changing the atm os
phere about the bodies of the occupants.
There is one other problem of atm ospheric pollu
tion to which special reference should be made. The presence of noxious fumes and still more the presence of fine inorganic or organic dust in the air constitutes a grave menace to health in m any processes and is an im portant contributory cause of tuberculosis. The normal body has its “ fighting e d ge” and can protect itself against the tubercle bacillus if given a fair chance, but the lung tissue which is lacerated b y sharp particles of granite or steel quickly succumbs
tion to which special reference should be made. The presence of noxious fumes and still more the presence of fine inorganic or organic dust in the air constitutes a grave menace to health in m any processes and is an im portant contributory cause of tuberculosis. The normal body has its “ fighting e d ge” and can protect itself against the tubercle bacillus if given a fair chance, but the lung tissue which is lacerated b y sharp particles of granite or steel quickly succumbs