366 HISTORY OF ACOUSTICS. 



more peculiarly the object of our attention. And 

 this consideration will explain why we have not 

 dwelt more upon the deductive labours of the great 

 analysts who have treated of this problem. 



To those who are acquainted with the high and 

 deserved fame which the labours of D'Alembert, 

 Euler, Lagrange, and others, upon this subject, 

 enjoy among mathematicians, it may seem as if we 

 had not given them their due prominence in our 

 sketch. But it is to be recollected here, as we have 

 already observed in the case of hydrodynamics, that 

 even when the general principles are uncontested, 

 mere mathematical deductions from them do not 

 belong to the history of physical science, except 

 when they point out laws which are intermediate 

 between the general principle and the individual 

 facts, and which observation may confirm. 



The business of constructing any science may be 

 figured as the task of forming a road on which our 

 reason can travel through a certain province of the 

 external world. We have to throw a bridge which 

 may lead from the chambers of our own thoughts, 

 from our speculative principles, to the distant shore 

 of material facts. But in all cases the abyss is too 

 wide to be crossed, except we can find some inter- 

 mediate points on which the piers of our structure 

 may rest. Mere facts, without connexion or law, 

 are only the rude stones hewn from the opposite 

 bank, of which our arches may, at some time, be 

 built. But mere hypothetical mathematical calcu- 



