560 THE INTELLECTUAL RISE IN ELECTRICITY. 



may, I think, without much difficulty be exceeded in 

 this way." 



Kinnersley, the ingenious, now appears with a variety 

 of amazing toys. He has made a magic picture of King 

 George with a golden crown on his head, and arranged 

 Leyden jar fashion, so that he who touched the gilded 

 frame and at the same time irreverently sought to grasp 

 the crown received a violent shock. ' ' God preserve him, ' ' 

 says the loyal Franklin, in mentioning the King's name; 

 but a few years later, men were indicted in Philadelphia 

 for sedition for saying just the opposite. There is also the 

 electrical jack a horizontal, wooden, pivoted disk, having 

 insulated brass thimbles around its edge which succes- 

 sively touch the wire of a charged jar and are repelled, 

 thus turning the disk; "and if a large fowl," adds Frank- 

 lin, u were spitted on the upright shaft, it would be car- 

 ried round before the fire with a motion fit for roasting." 



A much more elaborate electric motor was made from a 

 circular sheet of glass, coated on both sides and pivoted to 

 turn horizontally. The coatings alternately communi- 

 cated with bullets fixed at equal distances on the circum- 

 ference of the glass. Fixed near the disk were glass 

 supports carrying brass thimbles, and near these last the 

 bullets passed as they were carried around by the disk. 

 The wheel being charged, the bullets were alternately re- 

 pelled and attracted by the thimbles. Franklin says that 

 it ran for half an hour at a time at a speed of twenty turns 

 a minute, and Kinnersley applied it to ringing chimes and 

 actuating orreries. This was the first application of elec- 

 tricity to performing useful mechanical work. Father 

 Gordon's little reaction wheel had merely spun around and 

 driven nothing. 



The summer of 1749 was now at hand, and the Philadel- 

 phia experimenters determined to suspend work until after 

 the hot weather. Franklin, who does not conceal his re- 

 gret that "we have been hitherto able to produce nothing 

 in this way of use to mankind," ends his letter to Collin- 



