Royal Society. 301 



tical walls of each compartment to a plate at the back. This 

 plate has holes bored in it, through which the bars pass. A 

 plate of metal at the top and bottom close in the bulbs com- 

 pletely ; and the plates are secured in their places by four wires 

 bent twice at right angles and serving as clamps, as indicated in 

 the figure. 



XXXVI. Notices respecting New Books. 



Notes on the History, Methods, and Technological importance of De- 

 scriptive Geometry, compiled with reference to Technical Education 

 in France, Germany, and Great Britain. By Alexander W. Cun- 

 ningham. Edinburgh : Edmonston and Douglas. 1868. (Pp. 

 58.) 

 ^PHE titlepage of this tract almost sufficiently describes its contents. 

 -*- After a brief historical sketch of the various methods of repre- 

 senting solids in piano up to the time of Monge, the author gives in 

 general terms an account of the method of Descriptive Geometry. 

 He points out that the most fundamental department of industrial 

 art is that of Shaping matter by Tools, which is in fact constructive 

 solid Geometry. To this art that of Descriptive Geometry is strictly 

 correlative, inasmuch as it exhibits graphically on a plane what the 

 other realizes in solid matter ; in fact the working drawings com- 

 monly used in carpentry, stone-cutting, &c. are nothing but parti- 

 cular cases of an art which Descriptive Geometry treats generally. 



In the latter part of the tract the author notices the position as- 

 signed to the study of this subject in France and Germany, in con- 

 trast w 7 ith the scanty attention paid to it in England. He remarks 

 that whatever has been done in this country has directly originated 

 from government schools, and urges that this shows Government to 

 have been in this matter far ahead of the people. 



It is scarcely necessary to add that we thoroughly agree with Mr. 

 Cunningham as to the value of Descriptive Geometry, both in regard 

 to its direct applications to the arts, and to its use as an exercise for 

 clearing the student's conceptions of geometrical combinations in 

 space of three dimensions. 



XXXVII. Proceedings of Learned Societies, 



ROYAL SOCIETY. 



[Continued from p. 241.] 



February 20, 1868.— Dr. William Allen Miller, Treasurer and Vice- 

 President, in the Chair. 



Tj^HE following communication was read : — 



A " On the Resistance of the Air to the Motion of Elongated Pro- 

 jectiles having variously formed Heads." By the Rev. F. Bashforth, 



