610 KEPORT— 1893. 



drawing, a knowledge of some of the elements of the subject is expected. 

 On the continent of Europe, however, for many years, not only have 

 special courses of lectures been devoted to the teaching of graphic statics 

 as a separate branch of the subject, but there have been a large number 

 of schools in which there are special professors of graphical statics. The 

 reason for this difference is to be found, not altogether, as it is often 

 supposed, in a want of appreciation on the part of English engineers or 

 professors of graphical statics — for it was in England that the germ of 

 such methods was first developed by Rankine, Clerk Maxwell, Fleeming 

 Jenkin, and others — but because the system of appointing professors in 

 the special polytechnics devoted to the allied sciences is there in vogue 

 rather than in England, where one or two chairs of engineering are 

 added to other chairs of the university or university college. 



Now, it is iustrnctive to note the general method of instruction indi- 

 cated in the syllabuses of engineering schools, and which are even more 

 clearly shown in the various text-books on the subject. From these it is 

 clear that the general methods consist of giving certain rules, which may 

 be called general graphic methods, and which apply to addition, multi- 

 plication, powers, and extraction of roots, which may be regarded as 

 forming the introductory portion. This is followed by what may be 

 regarded as an introduction to statics, in which special stress is laid on 

 geometrical constructions, and the solution of many problems is given 

 which would otherwise be worked out by analysis. 



We may regard the well-known work of Culmann, ' Die graphische 

 Statik,' as the first important treatise of the kind, in which work were 

 collected problems of a general nature, under the title of ' Graphical 

 Calculation,' which occupied the first three chapters, under the respective 

 titles of ' Operations with Lines,' ' Rectification of Areas,' and the ' Recti- 

 fication of Solid Bodies,' the whole occupying seventy pages. In the second 

 editioM of his work two chapters are introduced on logarithms and calcu- 

 lating rules, this portion occupying in the second edition 150 pages. In 

 the second edition the preliminary portion of graphic statics, which 

 occupied 130 pages in the first, here takes up no less than 350 pages, and 

 is followed by 120 pages on the theory of the elements of elasticity, the 

 author unfortunately not living to complete the work on the lines which 

 he had planned out. One thing is particularly noteworthy, viz., the large 

 space occupied by constructions and propositions, which may be regarded 

 more or less of a general nature compared with the space devoted to the 

 solution of actual examples. The same thing occurs in the lucid and 

 valuable work of Bauschinger, 'Elementc der graphischen Statik,' in 

 which there are sixty-two pages devoted to what may be regarded as matter 

 of a general nature, and only thirty to the applications. In the work of 

 M. Levy, which is the standard work of France, although he has very 

 much reduced in the second edition the portion of purely geometrical 

 calculation, he occupies the whole of the first volume of between 500 and 

 600 pages with the ' Principles and Applications of Pure Graphic Statics.' 

 The same general facts are derived from a study of the detailed course 

 as set forth in the various programmes of technical schools, the general 

 conclusions being that a great deal of the matter taught under the head 

 of ' graphic statics ' contains general principles of graphic methods of 

 construction which might be taught apart from any applications at all ; 

 and its being so taught would be capable of its application, not only in 

 cases of statics, but in dyr.amics and hydro-mechanics. 



