196 



SCIENCE. 



[Vol. XIII. No. 319 



the motors through an overhead wire. In Europe there are several 

 successful examples of electric tramways in mines, and lately 

 Messrs. Immisch & Co. have built a new mine-locomotive from the 

 designs of Mr. Reckenzaun. Storage-cells are employed for sup- 

 plying current, and a single motor of four-horse power. The gear- 

 ing is peculiar. On the armature-spindle is a small phosphor- 

 bronze pinion. This gears into four steel pinions placed in the 

 same plane, and 90° distant from each other. These pinions are 

 bushed with gun-metal, and run on steel pins carried on a cast- 

 iron disk. The disk revolves on a journal turned outside of the 

 end of the motor-bearing. Outside of, but in the same plane with, 

 these pinions, is fixed an annular casting of gun-metal, with teeth 

 cut on the inside. The steel pinions gear into the ring, which 

 'forms a fulcrum on which they revolve when the motor-spindle 

 turns. The power is transmitted from the cast-iron disk by a 

 sprocket-pinion keyed to it on the inside next to the motor, and a 

 ■steel chain connects this sprocket-pinion to a suitable wheel 

 mounted on one of the axles, while the other axle is connected to 

 this by coupling-rods. The storage-battery consists of forty-four 

 modified Tatham cells, each box being 10 inches by 6^ inches, by 

 III inches high. The boxes are lead-lined, and arranged in sections 

 •of three in wooden trays. Each box contains nineteen plates 

 7 inches by 4^ inches, by -^ of an inch thick, and has a capacity of 

 150 ampere hours, the weight being 53 pounds. The rate of dis- 

 ■charge varies from 25 to 50 amperes, and sometimes, on starting, 

 this increases to 65 amperes. Taking 40 amperes as the average 

 rate, the weight of these cells for a discharge equivalent to one 

 horse-povkfer is nearly 500 pounds, and per horse-power-hour 

 ■storage-capacity, 134 pounds. The Messrs. Immisch are now 

 working on some improvements by which the capacity will be in- 

 creased. This locomotive, on a grade of i in 70, would just 

 move, with a load of twenty loaded cars equivalent to eleven tons. 

 With fifteen cars, weighing eight tons and a half, the speed was 

 three miles per hour, the current being 45 amperes at 100 volts 

 pressure. On a grade of I in 40 the maximum load was eight cars, 

 and on i in 25 it was six cars, the speed being a little over two 

 miles an hour. On the level the locomotive could draw thirty cars, 

 the current employed being 45 amperes. 



Telling Trees by Electricity. — Hitherto machines for 

 (lelling trees have been driven by steam-power, but this is some- 

 'times inconvenient, especially in thick woods ; and now the Lon- 

 ■don Times reports that electric power has recently been adopted 

 in the Galician forests. Usually in such machines the trunk is 

 •sawed, but in this case it is drilled. When the wood is of a soft 

 nature, the drill has a sweeping motion, and cuts into the trunk by 

 ! means of cutting edges on its sides. The drill is actuated by an 

 -electric motor mounted on a carriage, which is brought up close to 

 the tree and shackled to it. The motor is capable of turning 

 Tound its vertical axis ; and the drill is geared to it in such a man- 

 ner that it can turn through an arc of a circle and make a sweep- 

 Jing cut into the trunk. The first cut made, the drill is advanced a 

 •.few inches, and another section of the wood removed in the same 

 ■way, until the trunk is half severed. It is then clamped to keep 

 ■the cut from closing, and the operation continued until it would be 

 ■ unsafe to go on. The remainder is finished by a hand-saw or an 

 :axe. The current is conveyed to the motor by insulated leads 

 Ibrought through the forest from a generator placed in some con- 

 venient site. 



HEALTH MATTERS. 

 Public Inspection of Food. 



The following resolutions were offered by Dr. George Straw- 

 bridge at a recent meeting of the Philadelphia County Medical So- 

 ciety : — 



■" The Philadelphia County Medical Society begs to call the earn- 

 est attention of city councils and the Legislature of Pennsylvania to 

 the pressing need of provision for the inspection of all meat and 

 milk used as food, with a view of furnishing sound meat and milk 

 to the people. 



" The society would also urge the necessity of killing and de- 

 stroying all animals afflicted with tuberculosis, and the owner 

 •should be indemnified by the State. 



" The society also recommends that a committee of five be ap- 

 pointed by the president of the society, whose duty it shall be to 

 represent the society with a view of obtaining further information, 

 and to confer with other bodies acting in this matter." 



Dr. Strawbridge, in introducing his resolutions, said : " Statistics 

 as reliable as can be obtained make the statement not too broad, 

 that in Philadelphia, about the present time, there is from three to 

 three and one-half per cent of tuberculosed meat used, and from six 

 to eight per cent of tuberculosed milk. Here in Philadelphia to-day 

 there is no inspection of any kind. The best the board of health 

 could do was to obtain an appropriation of fifteen hundred dollars 

 for the appointment of a milk-inspector, who will probably start to 

 the stations to see how much water goes into the milk. Anybody 

 can dump any kind of food in Philadelphia, and we must take it ; 

 but if we refuse to eat it, we are told that we are not good citizens. 

 Meat ought to be inspected when alive, and also during the process 

 of slaughtering. Unless you can inspect the animal alive, and also 

 when the internal parts can be viewed, the inspection is useless. 

 In the inspection of milk, the principal thing is to see the cows that 

 give it, so that they are not diseased, and to inspect it at its place 

 of delivery." 



The resolutions were adopted, and a committee was appointed 

 consisting of Drs. Leffman, Huidekoper, Shakespeare, Osier, and 

 Cleeman. 



Cholera Contagion in Drinking- Water. — F. G. Mc- 

 Kean, chief engineer in the United States Navy, states that dur- 

 ing ten days in 1885, nine hundred persons died of cholera on the 

 island of Takashima in Japan, and that the disease often appears 

 on the island. Suspicion was drawn to the drinking-water, which 

 was brought from the mainland. During 1888 the use of this 

 water for drinking-purposes was abandoned, and distilled water 

 was used instead. Although cholera prevailed on the neighboring 

 islands, Takashima was entirely exempt. This exemption may 

 have been but a coincidence ; still, it is more than probable, from 

 our knowledge of this disease, that the purity of the drinking-water 

 is to be credited with the immunity which the population of the 

 island enjoyed. To be absolutely certain of this, will, however, re- 

 quire more continued observation. 



NOTES AND NEWS. 



In the "Sixth Biennial Report of the State Board of Agricul- 

 ture of Kansas," Mr. E. B. Cowgill, in the report on the sorghum- 

 sugar industry, says: "The season of 1888 has been looked upon 

 as the one which should settle the question as to the financial suc- 

 cess of the sorghum-sugar industry, and, fortunately for the incom- 

 ing industry, the answer must be taken as an affirmative one. It 

 is true that not all of the factories in Kansas are able to show bal- 

 ances of profit. The fact, however, that the favorable results ob- 

 tained in 1887 at Fort Scott have been more than repeated at that 

 place in 1888; that a factory at Topeka has demonstrated the 

 practicability of the sugar industry at that place ; and the further 

 fact that Conway Springs and Douglass, in the face of adverse 

 circumstances, have shown the industry to be independent of all 

 patented processes and machinery, — will go far toward assuring 

 all diligent inquirers of the success of the Northern sugar industry. 

 Indeed, upon the most careful study of the subject, I have no hesi- 

 tation in saying that the sorghum-sugar industry is now on such a 

 footing as to invite the investment of capital, where such invest- 

 ment is placed under good business management, efficient, prac- 

 tical skill, and competent, scientific direction." 



— A recent invention of Messrs. Randall & Carter, for the pres- 

 ervation of freestone from the effects of weather, was exhibited by 

 them at the Cannon Street Hotel, London, on Feb. 15, in the pres- 

 ence of a large number of architects and builders. Several speci- 

 mens of well-known oolitic freestones, which had been treated by 

 this process in such a manner as to make their surfaces quite hard 

 enough to be.polished, were shown. The process consists of treat- 

 ing the stone with a compound of milk of lime, acetic acid, and 

 cane-sugar (or molasses), which, when applied, soaks into it for a 

 depth of about half an inch, and produces a slight chemical change, 

 materially hardening it. The stone may either be entirely im- 



