THE ROYAL ARTILLERY INSTITUTION. 
411 
THE 
CONSTRAINED MOTION OF CONICAL WHEELS. 
LT.-COL. E. CLOSE, K.A. 
PROFESSOR OF ARTILLERY, R.M. ACADEMY. 
The particular form of wheel used throughout the British service has 
been chosen with the view of securing great strength and the best arrange¬ 
ment of its parts to withstand those more serious shocks to which it is 
especially exposed. The characteristics of this form are, considerable dish 
with little or no strut; this combination necessitating a corresponding 
inclination or “ hollow ” of the axletree-arm, and a tire, the exterior surface 
or periphery of which is conical. 
The form thus adopted, while exhibiting great strength, is hampered with 
two disadvantages, each of which directly tends to increase the draught. 
These are— 
(1) The “ grind,” or twist of the wheel. 
(2) The side-rub. 
Proceeding, then, to an investigation of the grind—which, so far as I am 
aware, has not been previously made—Eig. 1 represents an exaggerated 
Eig. 1. 
G 
