Book Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 edition. Excerpt: ...masses "will have no influence on the plumb-line." The effect of a subterranean deficiency of matter varies with the depth to which it extends: if the same deficiency of matter be distributed through various depths, the direction of the resultant deflection will be different for each depth, and the deflection will decrease as the depth, increases. Colonel Clarke's formula for the attraction of a mountain mass is pMsma _8mai)loge--_ By taking A negative we can apply this formula to a subterranean deficiency of mattes. Latitude observations are about to be taken on the meridian of 88 at intervale of 30 miles between Calcutta and Darjeeling. The results will show whether the plumb-lines at stations situated south of Mount Everest and Kinchingunga are deflected to the same extent as at Dehra Dun, and whether the compensation of the eastern Himalayas, is more perceptible than that of the western. f On the meridian of 80, Bamuaiiur is 54 miles and Jarura is 7G miles from the foot of the Sub-Himalayas; tka Table following page 14 shows that the deflectioa at Kamuapur is almost twice as great as at Joxura. Tf the area of the mass as defined by a-, a.x and r-, remains constant, and if the total deficiency of matter remains constant, that deficiency may be distributed through any depth h: as h, the depth, increases, p the density decreases, and ph remains constant. It is only in cases, when the depth is so large, that it is necessary to take h2 into account, that the compensating effect of a deficiency of matter below a mountain mass differs appreciably from the effect of a change in the density of the mountain mass itself. If we suppose the Himalayas exactly compensated by an underlying cavity, whose form and dimensions are the same as...