REVIEWS — MATHEMATICAL AND PHYSICAL SCIENCE, 371 



chauical arts. The causes, indeed, which called them forth are somewhat different 

 from those which are active in more abstract, though scarcely more difficult 

 studies. Increasing national wealth, numbers, and enterprise, are stimulants an 

 like the laurels, or eveu the golden medals of academies, and the quiet applause 

 of a few studious men. But the result is not less real, and the advance of know- 

 ledge scarcely more indirect. The master-pieces of civil engineering, — the steam 

 engine, the locomotive engine, and the tubular bridge, — are only experiments on 

 the powers of nature on a gigantic scale, and are not to be compassed without 

 inductive skill as remarkable and as truly philosophic as any effort which the man 

 of science exerts, save only the origination of great theories, of which one or two 

 in a hundred years may be considered a liberal allowance. Whilst then we claim 

 for Watt a place amongst the eminent contributors to the progress of science in 

 the eighteenth century, we must reserve a similar one for the Stephensons and 

 Brunels of the present : and, whilst we are proud of the changes wrought by the 

 increase of knowledge during the last twenty-five years on the face of society, we 

 must recollect that these very changes, and the inventions which have occasioned 

 them, have stamped perhaps the most characteristic feature — its intense practi- 

 calness—on the science itself of the same period. 



It may be doubted whether the above does full justice to the period 

 last mentioned, that in which we are now working. Judging by the 

 history of the past, it is dangerous, perhaps presumptuous, to decide 

 on the real value of labors which we view only in progress, or to esti- 

 mate the magnitudes of intellectual characters when our very proximity 

 to them confuses the judgment. The Principia was for years a sealed 

 hook to most of Newton's contemporaries, and few fellows of the itoyai 

 Society recognised in their unpretending secretary, Dr. Thomas Young, 

 the man whom the lapse of a quarter of a century would proclaim the 

 worthy inheritor of Nev crown. So it may be, that we do not 



yet seize the full importar of such investigations as those of Oersted 

 and Thomson ; that we do not foresee the results to which such prin- 

 ciples as Joule's Mechanical Equivalence of Heat may lead, or that we 

 fail to observe the significance of those obscure utterances of Faraday 

 in the midst of the brilliant discoveries for which we gladly applaud 

 him. Still more do we think Professor Forbes has underrated our 

 progress in pure mathematics — further on he writes : " No new calcu- 

 lus or great general method in analysis has resulted from these perse- 

 vering labors, whether of British or foreign mathematicians, but an 

 increased facility and power of applying the existing resources of 

 mathematics to the solution of large classes of problems, previously 

 intractable, or resolved only indirectly or by approximation." 



Now we think that the method which is known by the imperfect 

 title of the " separation of symbols," constitutes a really great and 

 distinct step in analysis, not so much on account of what has been 

 achieved by it directly, but in that it has led to a reconsideration of 



