254 Professor Forbes's Address to the British Association. 



which physically, as well as in their mathematical methods, have 

 the closest analogy to that case of the motion of fluids treated 

 of in the present volume, namely the Theory of Sound, and the 

 intimate constitution of liquids. When, in addition to these 

 reports, we shall have received that undertaken by Mr Whe- 

 well upon the mathematical theory of Magnetism, Electricity, 

 and Heafr, we shall undoubtedly possess the most complete out- 

 line extant, of a department of knowledge entirely of recent 

 date. 



In the science of Hydraulics, indeed, some progress in theory 

 has accompanied the increase of practical information, at least 

 since the time of Newton ; but in the other strictly practical 

 report of the present volume, that of Mr Barlow on the very 

 interesting subject of the strength of materials, little or nothing 

 has been done of much theoretical importance since the days of 

 Galileo. Circumstances, which it would be easy to point out, 

 prevent our setting out, except in rare cases, from unimpeach- 

 able data ; but several very interesting conclusions of general 

 application are derivable from well conducted experiments, and 

 the Association may claim some credit for having brought into 

 general notice the ingenious investigations of Mr Hodgkinson 

 of Manchester, more particularly alluded to in this paper. 



One report, and that the longest which has ever been printed 

 by the Association, remains to be mentioned. It is by Mr 

 Peacock on the present state of Mathematics. When we con- 

 sider the vast extent of the subject, and the extremely limited 

 number of persons, even in the whole of Europe, capable of 

 undertaking it, we must consider the production of a work of 

 so much labour as the present, which, as yet, is incomplete, but 

 which the author has promised to resume, as the best trophy 

 to which we can refer in proof of the entire efficiency of the As- 

 sociation, according to its original plan, — as a. proof of the 

 ability and the indefatigable industry which it has enlisted in 

 its service, — a? a proof that its aim is not the dissemination of 

 superficial literature, stamped with the effigy of science, and 

 lowered for the demand of the indolent and the careless, — but 

 that it is intended to refine the precious metal until it reaches 

 a state of chemical purity, not to alloy and coin it for the pur- 

 poses of a promiscuous and debased currency. Mr Peacock 



