430 THE INTELLECTUAL RISE IN ELECTRICITY. 



ably suggestive of the principle and operation of the 

 phonograph. 



Hooke's essay on the method of improving natural phil- 

 osophy is a forecast of possibilities replete with suggestion. 

 4 'There may be a possibility," he says, u that by otocous- 

 ticons 1 many sounds very far distant (I had almost said as 

 far off as some planets) may be made sensible. I cannot, 

 I confess, myself so far throw off prejudice as not to look 

 upon it as a very extravagant conjecture; but yet methinks 

 I should have the same thoughts of a conjecture to find out 

 a help for the eye to see the smaller parts and rocks of the 

 moon and to discover their height and shadow, before I 

 had seen or known the excellent contrivance of telescopes." 

 So, perhaps, he might not have thought the telephone or 

 even the photophone or the hearing of explosions in the 

 sun quite so marvelous as did those who came after him. 



He affirmed that electric light is due to the same cause 

 as heat that is, internal motion in the parts of the body. 

 To produce electric luminosity, however, it is not enough, 

 he says, merely to cause this internal motion, but certain 

 bodies such as diamonds, sugar, black silk, clean warmed 

 linen, or a cat's back must be rubbed and agitated up 

 to a certain degree, and then "the more you rub it the 

 more it shines, and any little stroke upon it with the nail 

 of one's finger when it so shines, will make it seem to 

 flash." That was written in 1680, and it appears to have 



^tocousticons were probably speaking tubes, an invention as old as 

 the Egyptians, and then newly coming into vogue. Burton (Anat. Mel., 

 part 2, | 2, mem. 4.), speaks of them as serving to aid hearing, as tele- 

 scopes do sight. Evelyn (Diary, 13 July, 1654), notes a hollow statue 

 contrived by Bishop Wilkins, " which gave a voice and uttered Words by 

 a long, concealed pipe which went to its mouth, whilst one speaks 

 through it at a good distance," something after the fashion of the talking 

 head of Albertus Magnus. The aroused interest in the transmission of 

 sound resulted in the invention of the speaking trumpet by Sir Samuel 

 Morland in 1671. Butler's lines in Hudibras 



" And speaks through hollow empty soul 



As through a trunk or whispering hole 

 allude to this. 



