122 ANNUAL OF SCIENTIFIC DISCOVERY. 



machine. Dry air is a very poor conductor of electricity, and when 

 a machine is excited in such an atmosphere the electricity will remain 

 in tension for a considerable time. But moisture in the air conducts 

 the electricity away, and when the moisture reaches a certain point the 

 fluid is removed so rapidly that the machine will not work. Prof. 

 Seely's invention consists in devices for making the action continuous 

 in all weathers. This is effected by surrounding the machine with a 

 glass case, and keeping the air within the case dry by means of chlo- 

 ride of calcium or other hygroscopic substance. It has been observed 

 that when the conductor of an electric current is interrupted in a way 

 to draw a spark across the break, the brilliancy of the spark varies 

 with the material by which the conductor is terminated at the break. 

 Prof. Seely is now engaged in experiments to ascertain what material 

 will produce the most intense light. 



If the apparatus works according to anticipation a cotton mill may 

 be lighted without any current expense, except the small power 

 required to turn the electrical machines. As in mills driven by water 

 there is always a surplus of power during the winter months, the only 

 time when lights are required, there would be no expense for this 

 light except the first cost of the apparatus, which would be quite mod- 

 erate. Scientific American. 



Fishing by the Electric Light. -An experiment has been recently 

 made at Dunkirk, France, to use the electric light in fishing at night. 

 The light was supplied by a pile on Bunsen's principle, composed of 

 about 50 elements, and it succeeded tolerably well, but the employ- 

 ment of the pile was attended with much inconvenience. It was then 

 determined to repeat the attempt with a magneto-electric machine. 

 The new experiments tried at Dunkirk and Ostend had a double ob- 

 ject 1, to prove how the light produced by the machine would act 

 under water; and, 2, to discover the effect the light would produce 

 on the fish. The first object was completely accomplished, and it is 

 now demonstrated that magneto-electric machines and the light they 

 produce are applicable to all submarine works. In fact, this light 

 was constant at 180 ft. under water, and it extended over a large sur- 

 face. The machine, nevertheless, was placed at a distance of more 

 than 300 ft. from the regulator of the electric light. The glass sides 

 of the lantern remained perfectly transparent, and the quantity of 

 coal consumed was less than if it were in the open air. 



THE ELECTRIC FLY. 



Mr. Charles Tomlinson communicates to the Philosophical Journal 

 an interesting account of many experiments made by him with the 

 little instrument used in connection with an electrical machine called 

 the electric fly, or mill, or tourniquet, which is formed of two or more 

 metallic radial arms, having their extremities bent at right angles and 

 brought to a fine point. As a preliminary explanation why he has 

 made these experiments, he gives various opinions of philosophers as 

 to the cause of its action. After detailing its backward revolutions in 

 the open air and under a glass vase, its inaction in rarefied air, its 

 increased action in turpentine, benzole, and paraffine oils in both di- 

 rections, and its forward motion in the air after a modification of its 

 points, he concludes, while inclining to the opinion of Cavello as a 



