December 12, iS 



90. 



SCIENCE. 



335 



their pioduct is as powerful as dynamite. The principal difiSculty 

 in arranging; the experiments was to decide in what way the 

 strenstb of the explosives should be tested, as no method yet in- 

 vented can be considered entirely satisfactory. Finally Lieut. 

 Walke decided to use the Quinan pressure gauge. The instrument 

 used consisted of a heavy block of wood upon which was bolted a 

 cast-iron block. In this block four wrought-iron guides were 

 twisted around the circumference of a circle four inches in diam- 

 eter, and were connected by a ring at their outer ends. A steel 

 plate was let into the block, and was flush with its upper surface. 

 The piston, which rested on a plug of lead, was of tempered steel 

 four inches in diameter and five inches long, and moved freely 

 between the guides. It weighed twelve pounds and a quarter. 

 On the top of this piston was a parabolic cavity to hold the charge 

 of esplo.=ive. The shot, made of tempered steel, was four inches 

 in diameter and ten inches long, weighing four pounds and a half. 

 It was bored down its centre to receive a capped fuze. To operate 

 the instrument, a plug or cylinder of lead was placed on the steel 

 plate, and the piston lowered gently down on it. The charge of 

 explosive being placed in the cavity, the shot was gently lowered 

 upon the piston. On tiring the charge, the shot is thrown out and 

 the piston forced down on the lead plug, which it compresses, the 

 amount of compression being a measure of the strength of the ex- 

 plosive. Twenty-seven explosives in all being tried, the results 

 were compared with those obtained with a sample of nitro- 

 glycerine, the strength of which was reckoned as 100. The re- 

 sults placed explosive gelatine and hellhoflSte l:rst with a strength 

 of 106.17; gun-cotton and dynamite had each a strength of over 

 80; einmeusite, a new American explosive, one of nearly 78; bel- 

 lite. one of 65 70; and melenite, the famous French explosive, 



which is not nearly so safe to handle as bellite, had a strength of 

 only 50.82. The above figures are of course not absolute, but 

 they, at any rate, show the order in which the various explosives 

 come. 



INDUSTRIAL NOTES. 

 A Model Electric-Light Plant. 



In April of last year the electric-light system of the Eureka 

 Electric Light Company of this city, then known as the Loomis 

 system, was illustrated and described in these columns. Since 

 that time the progress of the Eureka Company has been steady, 

 though not as rapid, perhaps, as that of its older and larger com- 

 petitors. Lighting and power plants have been installed in many 

 parts of the country, and many improvements, both mechanical 

 and electrical, have been made in minor details of the apparatus. 



One of the latest of the Eureka Company's installations is a 

 five-hundred light plant in the Vanderbilt Building, a large office 

 building on Nassau Street, this city. The dynamo, of five-hun- 

 dred-light capacity, is driven by a fifty -horse-power Fitchburg 

 engine the Evans friction cone (also described in these columns 

 some time ago) being used instead of belting, to transmit the 

 power from engine to dynamo. This friction cone admits of a 

 very compact arrangement of machinery, much less floor-space 

 being required, as the engine and dynamo stand close together. 

 This is an important consideration in modern office buildings, 

 especially where space is valuable. The installation as a whole 

 is one of the simpler and yet most complete, both electrically and 

 mechanically, to be found in this city. 



In dyspepsia the stomach 

 fails to assimilate the food. The 

 Acid Phosphate assists the 

 weakened stomach, making the 

 process of digestion natural and 

 easy. 



Dr. E. S. McCoME, Philadelphia, says: 



^'Used it in nervous dyspepsia, with suc- 

 cess." 



Dr. W. S. Leonard. Hinsdale, N. H., 

 says: 



" The best remedy for dyspepsia that ha 

 ever come under my notice." 



Dr. T. H. Andrews. Jefferson Medical 

 College, Philadelphia, says : 



" A wonderful remedy which gave me 

 most gratifying results in the worst forms of 

 dyspepsia' ' 



Descriptive pamphlet free. 



Rumford Chemical Worksi Providence, R. I. 



Beware of Substitutes and Imitations. 



CADTIOIV,— Be sure the word "Hors- 

 ford's" Is printed on the label. All others 

 are spurious. Never sold In bulk. 



BOOKS : Honr to Xlxcbauge them for 

 others. Send a postal to the Science exchange 

 .column (insertion free), stating briefly what you 

 want to exchange. Science, 47 Lafayette Place, 

 New York. 



MEANS 



HEALTH, VIGOR, VIVACITY, GOOD MORALS. 



Disinfection, to be effective, must be 

 continuous. But one device, namely, 

 the 



SHERMAN "KING" VAPORIZER 



meets this requirement. This appa- 

 ratus consists of an iron vessel with a 

 tightly fitting lid, held down with a 

 screw, and inclosing a porous cup, 

 which is saturated with a volatile dis- 

 infecting fluid. A small screw valve is 

 arranged on the side of the case. Open- 

 ing both lid and valve, a current of an- 

 tiseptic vapor issues, carrying with it 

 the volatile disinfectants. 



Simple, Self- Acting, Inexpensive, and 

 Infallible in operation ; it absolutely 

 purifies the schoolroom, hotel, dwelling, 

 sleeping car, and all places within 

 doors, however polluted. It is a power- 

 ful antiseptic, sterilizes disease germs, 

 preventing infection, and removes all 

 dangerous gases. 



Three sizes, $3.50, $6.00 and $8 00. Each 

 Vaporizer sold is filled ready for use. No care 

 except to replenish once in two months at a cost 

 of 4 to 8 cents, according to size. 



Illustrated Pamphlet Free. Address 



LYON M'F'G CO., 



59 FIFTH AVENUE, NE1V IfORK, 



Sole Agents for the Worlrl. 



As a Flesh Producer there can be 

 no question but that 



SCOTTS 



EMULSIONi 



I Of Pure God Liver Oil and Hypopliosphites 



I Of Lime and Soda 



is without a rival. Many have 

 grained a pound a day by the use 

 of it. It cures 



CONSUMPTiON, 



SCROFULA, BRONCHITIS, COUGHS AND! 

 COLDS, AND ALL FORMS OF WASTING DIS- 

 EASES. AS PALATABLE AS MILK. 

 Be sure you get the gemiine as there are 

 I poor imitations, 



TP 3E1. xsx:. 



OCR 100 pp. C.ITALOGCE OF MIKERAIiS. 



Illustrated with 57 cuts, and containing (a) Scien- 

 tific Papers and Notes, 41 pp.; (bj A Classified List 

 of All Mineral Species, giving chemical composition 

 and crystallographic form, 81 pp.; (c) An Alpha- 

 betical* Index of some 3,000 mineralogical names. 

 Paper-bound copies free to those mentioning this 

 journal; handsome cloth-bound copies. 25 cents, 

 postpaid. GEO. L. ENGLISH & CO.. Dealers in Min- 

 erals, 1512 Chestnut street, Philadelphia ; 739 & 741 

 Broadway, New York. 



yUST PUBLISHED. 



POPULAR MANUAL OF VISIBLE SPEECH ANE) 

 VOCAL PHYSIOLOGY. 



For use in Colleges and Normal Schools. Price 50 cents. 



Sent free by post by 



N. D C. HODGES, 4 7 Lafayette PI., N. Y. 



