with a level and a clamp; the level is fixed at the correct angle for drift; if the sight (as is especially liable to be artillery the case on steep hillsides) is tilted away from the angle sights.
The sights themselves fit into sockets cut at the proper angle for drift, and are raised in their sockets the requisite amount for the range by means of a small hand-wheel; they are thus non-recoiling sights.
the limiting angle for these media may be easily shown to be slightly above 152°.
The very high refractive power (index = 2.417 for sodium light) gives the stone its extraordinary brilliancy; for light incident within a diamond at a greater angle than 241° is reflected back into the stone instead of passing through it; the corresponding angle for glass is 401°.
The 2006 model frame has a steeper steering angle for more stable cornering.