J u l y , 1912
%’HE JOLJRAITAIA01; /~‘ViU~JSTRIRT2 AiVD E N G I N E E R I N G C H E M I S T R Y .
and convenient electrode holder can be used in conjunction with this form. Both electrodes are fastened t o a small block mTliich is raised with one harid while the wash bottle is used with the other. The objection might be raised t o our modification t.hat on account of the strong field a t the bottom of the beaker and the m-cbak one a t the top, most of thc stirring would be at the bottom. I t is true t h a t the vigorous stirring does originate at the bottom, but on account of the free circulation, the upper part of the solution gets all the stirring necessary. I n any event the solenoid stirring does not produce the commotion in the solution caused by a mechanical stirrelbut nevertheless results can be obtained quickly. T h ? avcra,ce strength nf the magnetic field nicasiircrl i n the rcyion o f the beaker is i o 0 gausscs. RESULTS. ( f>tar!- has describer1 in detail the speed and acc.urnc>. obtained hy the use o f a solenoid in electrolytic Tvnrk. )
‘l‘hc. f n u r scilviioids shoivn in Fig. 2 have becn in usc i n t.hc Chemical Dcpartmrnt ( i f the Pittsburg Tcstiti:
Laborator\- for several months and are vcr\- satisfactory for the large variety of determinations we arc called upon to make. TT’e recognize the) merits oE the various forms o f apparatus proposed for mechanical stirring b u t prefer our present equipment. K e find it much more satisfactory than the stationar!. gauze electrode alone where a variety of determinations arc to be made. With stationarJ- gauze c%lectrodesin 1 2 5 cc. of solution containing about one gram of copper we allowed three amperes t o pass for fifty minutes in order to be sure all the copper had been deposited. With thc solenoid the same amount of copper is deposited in thirty minutes under the same conditions using t h e same electrodes. With a higher current the results can be obtained in less timr. PITTSBURGH TESTING I,ARnR.\TnR\-,
CARNEGIE TECHNICAL ScHnnLs. ____.
THE
UNDERWRITERS’ LABORATORIES APPARATUS.
EXTRACTION
B y HENRY.I. CARY-CURR.
Received April 16, 1912
It has been found necessary in certain lines of cxtraction work t o devise for routine work a method t h a t is both rapid and convenient, such, for example,
53s
as the determination o f certain cxtractable constituents of rubber insulation on mire, ctc. I n such a case the moisture content (generally less than onehalf of I per cent.) is a negligible factor in the determination and may therefore be overlooked except in special cases where it is especially desired. Based on this ground the Chemical Department of the Underwriters’ Laboratories a t Chicago have spent several >-earsin developing methods and apparatus to be used in a standard procedure for chemical tests of rubber compounds used on wires and cords. Any form of extraction apparatus may be uscd, but i t must conform to the following spccificatinns: ( I ) “ The extraction cup shall be surrounded by thc vapor of the solvent a t its boiling point.” ( 2 ) “ T h r condensed solvent shall fall directly on thc sample.” (3) “ T h e outlet from thc extraction cup shall br a t the bottom only.” (4) “ Kn rubber or cnrk stoppers shall cotne in contact with thc solvent.” (5) “Samplt shall bc put directly into extraction. cui) without thc use oE a paper thimble--a disc o f filter paper or its equivalent a t the bottom o f thc cup bc-ing depcrirlc~l upon to hold hack thc sc~liclp a r t of thc. s:implc.” F ~ ~ l l c i m i tthc i ~ inanipula t i o i i i elf t l i c ;ihove-illc-ii tioncci mc-thocls i t f)rcrinics neccssul-!. t o r s t r a c t , i t i t r i ;I tarccl flask \rhich rnust h~ r c w c i ~ h c r l: r i i i l Lvhich n ~ u s t thcrcfot-e hc. o f proportions xnd st!-lc suitahlc lor ariinissicin to t h c s hoivs ant1 1)aiis ( i f a i l i i r c l i n a r ~;inal~~tic:~l ~ halancr. liapiclit!. ani1 ct7icif,ni,!- 01’ c o i i ( 1 u i s a t i o i i tiigct hci. I\ i t h (’as? o f i~ianipulatioii ; i i i i l i n ~ t a l l ai tc i r i \\,ell ; I < simplicit!. i~l‘c~onstructionanti thcrciorc’ Ii)\v c,rist 01 tnaintenanccxrinli rcplacemtTnt\ \ w e other points t ( Jhc. ronsiderctl. To meet thcse requirements R t i r \ v apparat 11s h a s ceptional merit I t consists of a short, metallic, spiral-titbc reflux condenser, whose, inlet and outlet tubes project metal platc through n hich scrx c\ the double purpose o f a support for the condenser and a closure for the extraction flask The flask is of rather conical form with rt long neck and flat Two holes arc bottom horecl on opposite sidei ot t h e upper rim of a 1)oixclain Gnoch cruciblc i\ hich is suspended from t hc condenser by passing through the holes a short piece o f platinum 01 aluminum TT ire whichalso passes through the loop a t the bottom of the condenser. The charge having been placed in the crucible, the condenser and crucible are placed in the neck of the flask, the water connections made and when a good flow of water has been c~
I
53 6
T H E J O U R N A L O F I N D U S T R I A I , A N D E N G I N E E R I N G CHE.MISI'K Y.
established, heat is applied t o the flask and the action is carried on automatically. The evaporated solvent is condensed on the spiral coil and drops into t h e crucible, passing through t h e sample into the flask where i t is again volatilized and the cycle is repeated. As the whole apparatus is only 6" high and 3" wide i t takes up the minimum of space, and where much work of this character is done a battery of extractors a n d flasks can be arranged on a hot plate or water
I B y CHARLES
E. MUNROE.
When speaking of the gas industry our mind naturally reverts t o those public service corporations t h a t are manufacturing gas for distribution and sale, and i t is interesting t o note t h a t we are almost touching the centenary of their origin, a n event which has proved of such importance in the development of civilization and in making life in dense communities feasible, a n d relatively secure, as to be worthy of commemoration ; for, although, following Murdoch's demonstration atTR.edruth, in Cornwall, England, in 1792, several isolated plants for lighting houses and factories were built and operated, the gas industry as we now regard i t , with its central producing plant connected b y mains and services with a multitude of consumers began when, in April, I 8 I 2, a Royal Charter of Incorporation was granted to the Chartered Gaslight and Coke Company of London, England. In the United States, although isolated plants of an experimental nature are recorded as having previously been erected a t Newport, R. I . , and Richmond, Va., this industry began with the chartering of a gas company in Baltimore, Maryland, in 1816. GAS INDUSTRY, Number of establishments ....... ....... 1.296 Capital ....... . . . . . . . . $915,537,000 ........ 52,428,000 Cost of materials u s e d . . . . . . . . . . . . . . . . Salaries and wages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33,316,000 Salaries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12,385,000 20,931,000 ................................. Miscellaneous expenses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27,757,000 . . . . . . 166,s14,000 Value of products.. ........................ Value added by manufacture (products less cost Employees: Number of salaried officials and clerks.. 13,515 e earners employed during the 37,215 128,350 Primary horsepower ................
.................
............. ............................ .....
P S. Total gas produced.. . . . . . . . . . . . . . . . . . . . . . . . . ?150,835,793,000 CU. ft. Straight c o a l . . . . . . . i . . . . . . . . . . . . . . . . . . . . . '19,985,253,000 '' Straight water.. . . . . . . . . . . . . . . ....... 1,726,082,000 " '' Carbureted water. . . . . . . . . . . . . . . . . . . . . . . . . 79,418,486,000 " Mixed coal and water.. . . . . . . . . . . . . . . . . . . . 40,775,283.000 " " Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,688,860,000 '' ................ 225,186,000 " " 216,643,000 " " 2 82,049,683,000 hu. 2 92,152,938,000 gal. Address before the Division of Industrial and Engineering Chemistry, Annual Meeting A. C. S., Washington, December, 1911. 2 I n addition, 27,558 thousand cubic feet of straight coal gas, 13,070 thousand cubic feet of acetylene gas, 44,347 bushels of coke, and 38,370 gallons of tar were produced for sale by establishments engaged primarily in the manufacture of other products.
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..
1912
bathof verysmalldimensions, say two rows of tenor more flasks, in which case the b a t h can be furnished with a set of spring clips to steady the flasks when one of the set is removed. The water flowing from one condenser to the other only onr inlet and one outlet is needed. Copies of the Standard Methods alluded t o above may be obtained from the Underwriters' Laboratories of Chicago; the apparatus from E. H. Sargent & Co., of Chicago. CHICAGO.
ADDRFSES
THE PRESENT STATUS OF THE GAS INDUSTRY AND ITS OUTLOOK.
July,
I
The present status of this industry in the United States is approximately set forth in the preceding table, wherein the statistics given are those collected by the Bureau of the Census for t h e year ending December 31, 1909; they show to what enormous dimensions this industry has grown in this country in less than one hundred years. I n presenting these statistics I must, as I have on several previous occasions, call your attention t o the limitations placed on census statistics, in common with all other bookkeeping statistics, growing out of the necessity for keeping each category carefully separated. Thus while in the foot-note there is given the statistics for those establishments t h a t manufacture "artificial gas for sale" as a subsidiary product, there is not included in the table or foot-note t h e natural gas produced for sale, since this is not manufactured, nor the blast furnace gas or producer gas, since while these are manufactured they are not produced for sale b u t are consumed by the establishments manufacturing them. Likewise, though the by-products coke oven gas produced for sale is included in the statistics of the table when such establishments are primarily engaged in producing gas for sale, yet the gas from the larger number of by-product plants, and also the coke and t a r produced b y them, is not included in the table since these products are chiefly consumed by the establishments of which they form a part. Such gas, however, as has been sold by these last mentioned establishments to gas companies appears in the tablc b y value, though not by quantity. A comprehensive treatment of all gas industries would include the statistics for gas from all thesc sources, a n d I hope t o be able later to present them. It is to be noted t h a t the Chartered Gaslight and Coke Company a n d the Baltimore Gas Company made coal gas b y the destructive distillation of bituminou5 coal The table includes water gas, mixed coal and water gas, oil gas, and acetylene gas in addition to coal gas. I n quantity, carbureted water gas exceeds them all, and if the straight water gas together with t h a t used in compounding the mixed gas be also regarded, water gas greatly exceeds in quantity all other gases combined. There may be some little surprise a t finding acetylene gas and oil gas carried in this account for they are not usually thought of as being handled by public service corporations, yet to-daJ- there are a considerable number of smaller
