Dec., 1918
T H E J O U R N A L OF I N D U S T R I A L A N D EJGINEERING C H E M I S T R Y
tion between t h e atmosphere in t h e lower flask and the atmosphere in the upper flask. One arm of t h e stopcock is extended until it opens above t h e liquid in t h e upper container. The liquid enters a t an aperture in t h e lower part of this ixtended a r m and is delivered through a small glass tube sealed in a t this opening. The entire arrangeme& is more clearly understood by a glance at th? accompanying diagram. Two different styles were made, using t h e same principle in each.
1 0 1 5'
I wish t o acknowledge my thanks t o Mr. W. Wiegand of the firm of Eimer and Amend, NewYork City, for his interest and skill in making these two stopcocks. LABORATORY OF ORGANIC CHEMISTRY UNIVERSITY,NBW Y O R ECITY CGLUMELA
A NEW TIMING DEVICE FOR SIMPLIFYING THE THERMOMETRIC READING O F CALORIMETRIC DETERMINATIONS By CHAS. A. MYRRS,JR.
Received M a y 18, 1918
A t the beginning of the war the chemical laboratory of the New York Navy Yard was called upon t o do all t h e chemical analyses of coal used by t h e fleet and its auxiliaries in the northern district. This wrought a tremendous increase in the work which t h e laboratory in normal times was expected t o do; b u t notwithstanding the increase in t h e number of analyses i t was essential t h a t there should not be any sacrifice in the accuracy t o which these operations were ordinarily accustom-d. The writer, who has for some time been engaged in the work in question, has developed an electrical timing device for calorimeters which he believes would be of great assistance t o anyone called upon t o determine calorific values under such circumstances, where radiation factors are involved. One of the chief advantages of this timing device is its absolute accuracy in giving the operator t h e exact second a t which t o read t h e thermometer. The instrument, moreover, relieves t o an almost unbelievable
F I G . 1 -LONGITUDINAL SECTION F r o . la-Cnoss SECTION AT CENTER FIG. 2 -LONGITUDINAL SECTION
ADDITIONAL
DIMENSIONS
Fig. 1 Mm. 35 5 3
.................. .............
Length of stopcock barrel. Outside diameter of inner tube.. Inside diameter of inner t u b e . . Outqide diameter of outer t u b e . . Inside diameter of outer t u b e . .
.............. ............ ..............
10 7
Fig. 2 Mm. 35 5 3 13 9.5
If t h e flasks are used as shown they must be securely fastened by clamps close t o t h e lips. The upper flask can be filled through a funnel attached by means of a piece of rubber tubing. The liquid will flow down the inside walls and not drop into t h e extended tube. The arrangement and kind of flasks can be changed as desired, and i t is believed t h a t t h e apparatus will be of service elsewhere.
FIG
I
extent the strain on the operator who may be called upon t o make constant readings over an extended period of time. With this device i t is no longer necessary t o divide attention between the stop watch and the thermomzter, first looking a t onz and then the other, as an audible warning signal is given 5 seconds before thz time t o read, and a second signal a t t h e moment a t which t h e reading should be taken.
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 Vol.
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IO,
No.
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FIG.I1
A further advantage is t h a t almost any number of calorimeters may be operated a t one time by this device, it being simply necessary t o have the signals loud enough to be heard bx all of the operators. The device copsists of a clock p u t out by one of t h e large photographic supply houses which has a large second hand maklng one complete revolution every minute. On t h e face of this clock are cemented four platinum-foil squares arranged so t h a t contact will be made 5 seconds before the minute and half-minute, and again exactly on the minute and half-minute. Contact is made by a fine platinum wire soldered t o the second hand of the clock. Two buzzers are used t o give t h e signals, one of high pitch and the other low. The writer selected the high-pitch buzzer t o give t h e warning signal 5 seconds before the time t o read and the low-pitch buzzer for t h e signal t o read. AS the buzzers consume a relatively large amount of current i t is impossible t o make contact for them directly through the platinum wire and t h e contacts really operate two relays and these in turn pass the
current through the buzzers. The relays are made from common nails about 1'/2 in. long turned down in a lathe and wound with eight layers of No. 36 double silk covered copper wire. A small piece of platinum is soldered t o the end of one of t h e magnets of each relay ( the one furthest from the hinge) and this makes contact with another piece of platinum soldered t o t h e armature, thus closing the circuit t o the proper buzzer. The relay magnets and their supports are mounted on a hard rubber base which insulates the armature from the magnets when current is not flowing through the latter. -4 double switch is provided t o cut out t h e half-minute readings when these are not desired and a single point switch t o shut off all readings. T h e details of the wiring are shown clearly in Fig. 111. CHEMICAL LABORATORY NAVY Y A R D BROOKLYN, N . Y.
ADDRESSES SOME APPLICATIONS OF PHYSICAL CHEMISTRY IN THE COAL-TAR INDUSTRY By WILBERTJ. HUFF
This paper will be divided into two distinct parts, the first of which deals with volume relations in solidifying creosotes, while the second applies to the vapor densities of coal-tar fractions. I--VOLUME
RELATIONS OF SOLIDIFYING CREOSOTES
Since liquid coal-tar products are regularly sold by volume, the exact determination of the variation of volume with temperature is of great economic importance to both distiller and consumer. The standard temperature for oil measurements is usually 60' F., although in the case of creosote oil 100' F. has been somewhat generally adopted. Since it is obviously 1 Read before the New Yotk Section of the Society of Chemical Industry, May 24, 1918.
impossible to bring tank car quantities to the standard temperature before gauging their volume, the shipper determines the volume a t the shipping temperature and calculates the volume at 60' F. by means of a coefficient of cubical expansion; the receiver invoices at the temperature a t which he happens to get the car and calculates by means of the same coefficient to the same temperature. Now the trade has found it difficult t o obtain concordant results between measurements taken a t shipping and receiving points on creosote oil in tank cars and tank vessels. The discrepancies have in some instances amounted t o as much as 5 per cent of the volume of oil handled. Adjustments, however, were necessary not only in companyconsumer shipments, but also in inter-plant shipments, and even in inventory calculations a t the same plant. Clearly, something was wrong. Some earlier work on volume relations in creosote oil was car-
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