534 



HISTORY OF SCIENCE. 



suffice to mark the course of the science have been, for the sake of 

 continuity, reserved for presentation in this place. Many of the re- 

 searches belonging to this science are of a highly mathematical form, 

 and therefore unsuited for our purpose. Such were the investigations 

 of Newton, Leibnitz, the Bernouillis, Euler, D'Alembert, and others. 

 Passing by all these deductive investigations, we shall mention some 

 experiments of importance in the development of our knowledge of 

 Sound. 



The part played by the air in the conveyance of sound from the 

 sounding body to the ear was, soon after the invention of the air-pump, 

 experimentally proved by Hawksbee. The now well-known experi- 

 ment is represented in Fig. 248, where on the 

 plate of the air-pump is seen a case contain- 

 ing clockwork, resting at B B on felt supports 

 to prevent the vibrations passing to the plate 

 of the pump. The clockwork causes a ham- 

 mer to strike the bell T, and when this is done 

 in the exhausted receiver, scarcely any sound 

 reaches the ear ; but when the air is admitted, 

 the bell is heard, faintly at first, but soon with 

 its full power? 



The vibrations of strings were theoretically 

 and experimentally investigated about the 

 beginning of the eighteenth, century by New- 

 ton and by Euler, and ly SAUVEUR (1653 

 1716). In Sauveur's life there is a curious 

 circumstance that, in relation to the researches 

 for which he became famous, appears still more 

 curious. The first seven years of his life he 

 was quite dumb, nor did his vocal organs ever 

 attain their full development. The man who first counted the actual 

 numbers of the impulses which give the notes of the musical scale had 

 himself neither voice nor ear, and in his experiments on the vibration 

 rates of strings of different lengths, tensions, etc., he had to rely upon 

 the assistance of friends for the discrimination of consonances and 

 dissonances. Sauveur was originally destined for an ecclesiastical 

 career, although early in life he had manifested great delight in me- 

 chanical contrivances and arithmetical computations. A copy of 

 Euclid's " Elements of Geometry," which the youth accidentally met 

 with, determined the course of his after-life. He abandoned the 

 training which was to qualify him for the Church, and having in con- 

 sequence lost the support of his relatives, he obtained a livelihood by 

 teaching mathematics. By good fortune he found an appreciative 

 patron, through whom he obtained in 1686 an appointment as pro- 

 fessor of mathematics. During the remainder of his life, the study 

 of acoustics, and particularly the scientific theory of music, occupied 



FIG. 248. 



