1874.) Notices of Books. 397 
stability,” and he carries his argument out fully to prove that the 
present metacentric method of calculation is erroneous. The 
question of buoyancy is next dealt with ina manner which leaves 
Mr. Reed but little cause to be satisfied with his own perform- 
ances. In our ironclads great buoyancy is given at the bottom 
of the vessel, whilst the heavy armour plating on the sides gives 
weight where buoyancy should exist, for it is at this very point 
where the life-belt of the ship should be placed. But Admiral 
Fishbourne is not content with merely stating his arguments at 
length, but they are supported at length by mathematical calcu- 
lations which leave no grounds for concluding otherwise than 
that his theory is based upon true scientific principle. 
Practical Solid or Descriptive Geometry. By W. TIMBRELL 
Pierce, Architect, late Lecturer on Geometrical Drawing 
at King’s College, London (vice Prof. Bradley), and Harrow 
School. London: Longmans, Green, and Co. 1871. 
Tuts is a work which has doubtless often been needed by the 
student of practical solid Geometry. Although many excellent 
works of this character exist in foreign languages, we have none 
of a really useful character published in English. A thorough 
knowledge of the principles of descriptive geometry is needed 
by many professional men, to enable them to represent solid 
objects on a plane surface, and hence its application to all the 
arts of construction, such as architecture, engineering, fortifica- 
tion, &c. To the artist, also, a knowledge of this subject is 
most important, as enabling him to draw in true perspective, 
cast the shadows of objects truly, and obtain the true position of 
the locus of greatest light on an object. 
The first part of this work treats on orthographic projection, 
and is divided into six chapters as follows :—I. Definitions, &c. ; 
Projections of Points and Lines. II. On Straight Lines and 
Planes. III. The Five Regular Solids, viz., the Tetrahedron, 
the Cube, the Octohedron, the Dodecahedron, and the Icosa- 
hedron. IV. Consists of Examples and Problems illustrating the 
principles of construction contained in the preceding chapters. 
V. On Section Planes and the Intersections of Solids. VI. On 
Tangent Planes and Surfaces in Contact. 
The second part of the book is on Perspective, or Radial Pro- 
jection, which is the application of the principles, enunciated in 
the first part, to practice on a plane surface: their application to 
the several arts of construction is a further development of the 
subject, which Mr. Pierce promises to explain in a future work. 
The careful manner in which the student is gradually advanced 
from one point to another, through the pages of this book, must 
render it one of great value to the student as a text-book, whilst 
VOL. IV. (N.S.) 3E 
