Nipher—Gravitational Repulsion. 185 
large masses and screen. A sketch of this arrangement 
is shown in Fig. 3. The sheets of metal which carried 
these pins were punched with small holes, through which 
Fig. 3. 
the pins were inserted and the heads were then soldered 
to the sheets of metal, which were then hung upon the 
insulated rods by metal hooks. At one end this line of 
rods terminated in a dise of metal upon which 150 pins 
were mounted. Facing this disc was a duplicate, the 
points of the pins in the two discs being three or four 
inches apart. This last named disc was directly con- 
nected with one terminal of an influence machine in an 
adjoining room, the other terminal being grounded on a 
water pipe. There were no condensers attached to the 
machine, and the knobs were widely separated. There 
were no gaps in the line of conductors. The machine was 
