T H E J O U R N A L OF I N D C 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
87 2
Ten samples of commercial feeds were used a n d t h e results obtained for each of these feeds, using t h e official method for t h e determination, appear above. It can readily be seen from t h e above results t h a t t h e new apparatus gave better extraction in t h e greatest number of cases, a n d averages higher in 8 out of t h e T O cases here noted. I t was found, too, t h a t there is a greater uniformity in t h e results obtained, it being necessary in several instances t o make as many as six determinations with t h e straight extraction apparatus .and four with t h e Soxhlet before checks within 0.2 per c e n t could be obtained. T o summarize, t h e apparatus gives better extraction t h a n does either t h e straight extraction or t h e Soxhlet methods. I t is easy t o manipulate, presenting a smooth outer surface, reducing t h e danger of breakage t o a minimum. T h e recovery of t h e solvent is easy a n d rapid a n d entails no loss of time. The cost of t h e a p p a r a t u s is also comparatively small. Acknowledgment should be made t o Mr. A. P. Kerr, Assistant Director of this station, for his suggestions. LOUISIANA AGRICULTURAL EXPERIMENT STATION BATONROUGE,LOUISIANA
A SIMPLE, DURABLE, ELECTRICALLY OPERATED GAS-VALVE By ZENO OSTENBERG Received June, 21, 1915
T h e valve herewith illustrated was designed a n d built t o regulate t h e flame of a double-burner gas-stove, which heated a large water b a t h 24 in. in diameter. Since two of them have been in operation for over a year a n d a half, with entire success, i t was thought t h a t a description a n d illustration of t h e mechanism would be useful t o others. T h e mechanism consists essentially of t h e “ironclad” electromagnet A , which lifts t h e iron disc B t o which is attached t h e brass valve a n d stem C. T h e brass valve C makes a gas-tight fit with t h e main brass body D at t h e inlet E when no current is passing T
c
E
through t h e magnet winding, b u t when CUrrent is sent through the magnet the disc and .C are raised a n d t h u s gas is allowed t o pass from E
Vol. 7, ?;o. I O
t o K , which leads t o t h e burner. F is t h e outlet t o a pilot light. T h e disc B is prevented from sticking t o t h e magnet A b y t h e plug S , which m a y be screwed down t o limit t h e travel of t h e valve s t e m C . G is insulation which must be able t o withstand a rise of temperature u p t o about IOO’, as t h e magnet sometimes becomes quite hot. T h e disc H is of brass a n d is soldered gas-tight t o t h e magnet A t o prevent moisture a n d gas from attacking t h e wiring a n d also t o keep t h e wiring in place. T h e gas inlet t u b e (not shown) enters opposite t o t h e pilot opening F. When opera t e d from a I I O volt line, t h e winding consists of No. 2 6 d. c. c. copper wire with a 16 c. P . carbon lamp in series. This allows slightly less t h a n 0.5 ampere t o pass through t h e winding of t h e electromagnet. F o r use with a storage battery No. 30 wire is used. T h e electrical circuit is opened and closed by a 7 5 o h m standard Pony relay, which is operated b y a d r y battery a n d thermoregulator. The dry batteries, which were originally p u t into t h e thermo-regulator circuits over a year a n d half ago, are still able t o operate t h e relays as only about 0 . 0 2 ampere is used, a n d this amount of current is so small t h a t no trouble whatever has been experienced from oxidation of t h e mercury at t h e contacts in t h e thermo-regulators. Obviously t h e valve may be used on a n y size of burner, f r o m t h e smallest micro-bunsen t o one which has a gas inlet equal in size t o t h e inlet a n d outlet of t h e valve. I n t h e valves in use these holes are 0 . 2 5 inch in diameter. 2233 WEESTER ST., S A N FRANCISCO
PORTABLE TITRATING TABLE1 By R.
E. Ozras
Received June 16, 1915
Fig. I shows a convenient portable titrating table which has recently been installed in t h e United States Appraiser’s Laboratory at New York. The burettes are operated b y compressed air supplied by a Goodyear air bottle which rests on a shelf attached t o t h e table. T h e air is conducted through ‘/8 in. a n d l / k in. brass pipe t o t h e main pipe ( I in. diameter), on t o p of table, on which are seen t h e air pressure gauge a n d t h e individual t a p s fitted with ‘/a Lunkenheimer brass spring key cocks. The t o p of t h e table is 3 ft. X 6 f t . a n d is perforated with 8 circular oaenings, j in. in diameter, in which t h e bottles are placed, resting on a base board securely fastened j in. below t h e t o p . T h e standard solution bottles are of dark glass, 2 5 0 0 cc. capacity, a n d as shown are eight in number. Without necessarily increasing t h e size of t h e table, a second row of eight bottles could be placed in a similar position a n d t h u s give i t a capacity of sixteen standard solutions. N o moisture or carbonic absorption apparatus is shown on t h e train, as t h e solutions employed did not require their use, b u t when necessary those accessories 1 Published Rith the consent of the Secretary of the Treasury and United States Appraiser. Port of N e w York.
