prisms (turned to ex- pins, which serve as pivots for the clamping rods or stretch- which the summits are directed in opposite directions on ers, B, Fig. 2. Lastly, over the wheel a cap (broken away tinction), there are obtained, by causing the parallel rays to each side of the point of division.… … imbedding the tubes in plaster and cutting them in the mid- this difference, that the effects due to temper are permanent, The stretchers, B, are formed with lugs on their under dle, to the right and left of the cut will be observed the con- while those which result from flexion disappear as soon…
