510 ON THE DIFFEEENTIAL COEFFICIENTS AND DETEEMINANTS OF LINES. 
Now 2mdet(R, V) equals the complete sum of the moment-axes of the momenta, or 
is, in other words, the axis of the body’s momentum couple H whose components are 
Aw^,, Cra-,. Hence we see that 
Sm det (R, det (O, V))r=det (O, H), 
and therefore the sum of the moments about Ox of the moving force, of which 
711 det (O, V) is the type, is the component parallel to x of det (O, H), and equals 
therefore ( C — 
