422 REPOUT-1892. 



Mr. James B. Chalmers, in the preface of liis treatise on the same 

 subject,^ writes as follows : — 



' The following treatise is confined to the more valuable applications 

 of the graphical method, the creation of Professor Culmann, of Zurich. 

 "Were a preference for this method once established, it might then in 

 England, as now in Germany and Italy, be built up into a systematic 

 discipline, remarkably fitted to exercise the intellectual powers. Begin- 

 ning with projective geometry as founded by Poncelet, followed by geo- 

 metric statics as taught by Mobius, the Gahul -par le trait of Cousinery, 

 the properties of the Funicular Polygon of Varignon, so remarkably 

 extended and employed by Culmann, and their application to the Elastic 

 Line by Mohr, we should have a course of engineering mechanics so 

 invigorating to the mind that our students, having undergone its disci- 

 pline, would feel themselves men well pi'epared for work, capable of 

 appreciating the conditions and reasoning upon the data of a large class 

 of practical questions to which they might require to address themselves. 



' From its birthplace in Switzerland, 1860, this method has passed 

 into Germany, Austria, Italy, Russia, and Denmark, where, after Cul- 

 mann, Wilhelm Hitter, Cremona, Favaro, and many others, have com- 

 municated their enthusiasm to their pupils, through whose superior 

 discipline their respective countries may soon rival in engineering fame 

 that of the country which we fondly regard as its cradle, and as its most 

 able instructress. 



' The reason we apprehend lies, first of all, in its geometric character. 

 The designs of an engineer are geometric conceptions ; his structures are 

 geometric forms, within which forces statically combined act along geo- 

 metric lines, so that it is natural that he strive to follow a train of geo- 

 metric thought.' 



Still another writer may well be quoted, representing an American 

 point of view. Mr. Jay Du Bois says, in his work on graphic statics : — ^ 



' For the practical engineer the importance of graphical methods 

 needs, indeed, to-day no demonstration. Such methods are everywhere 

 in use. But a simple and general system, which shall include all such 

 solutions, and fi'om which they all flow, is, at least in this country, 

 unknown. Even in English literature there is to be found little more 

 than the very elementary deductions of our first chapter, so that it 

 may justly be said that the entire method owes its existence and develop- 

 ment to the labours of German scholars, and the enlightened appreciation 

 of German engineers.' 



Now it is to be noted that all these are writing, not of the actual 

 solution of problems by graphical means, but on the general adoption of 

 the geometrical basis of approaching such problems, though this is not 

 so clearly indicated as it might be in the first portion quoted of Mr. 

 Chalmers's remarks. Indeed, no one would deny that not only in graphi- 

 cal representation, already dealt with, but in the mechanical treatment 

 of, at any rate, one class of problems, viz., framework, English engineers 

 are in nowise behind, and it is a usual thing in engineering journals in 

 this country for graphic diagrams of stress to be given when illustrating 



' Graphical Determination of Forces in Engineering Strnctures, by .James 1?. 

 Chalmers, C.E., 1881. Macmillan & Co., London. 



- The Elements of Graphical Statics and their Application to Framed Structures, 

 b3' Jay Du Bois. ISS:^. .lohn Wiley & Sons, New York. 



