ROBERT HOOKE'S EXPERIMENTS. 429 



is a tendency now to come back. He experimented in 

 about every known branch of physics, but he shone 'most 

 as a contriver of measuring instruments. In this respect 

 no predecessor approaches him in ingenuity and skill; very 

 few have since equaled him. He was the first curator of 

 the Royal Society, and whenever anything was to be in- 

 vestigated, it was Hooke who evolved the mechanical 

 devices for doing so. Clocks and chronometers, astronom- 

 ical apparatus in great variety, instruments for measuring 

 specific weight, refraction, velocity of falling bodies, freez- 

 ing and boiling points, strength of gunpowder, vibrations 

 of dense bodies, degrees on the earth, magnetism, and so 

 on through such a variety and multiplicity of mechanisms 

 that it may be imagined that of the many 'scopes, 'graphs, 

 and meters which now sharpen the senses of modern physi- 

 cists, few exist in which something originally emanating 

 from Hooke's tireless brain cannot be found. His volute 

 spring, opposing and counterbalancing the motion of a 

 rotary arbor in all positions, which made the pendulum 

 clock into the portable chronometer, now weighs the pres- 

 sure of the electric current, and in the same way has ren- 

 dered electrical instruments portable. 1 And as for the 

 foreshadowing of modern achievements, we are told by 

 Richard Waller, secretary of the Royal Society, his bi- 

 ographer and immediate personal friend, that u he shewed 

 a way of making musical and other sounds by the striking 

 of the teeth of several brass wheels proportionally cut as 

 to their numbers and turned very fast round, in which it 

 was observable that the equal or proportional strokes of 

 the teeth, that is 2 to i, 4 to 3, etc., made the musical 

 notes, but the unequal strokes of the teeth more answered 

 to the sound of the voice in speaking" which is remark- 



1 Butler in Hudibras alludes to Hooke's spiral spring and its effects in 

 the lines: 



" And did not doubt to bring the wretches 

 To serve for pendulums to watches 

 Which, modern virtuosi say, 

 Incline for hanging every way." 



