Penny Blood: Serial Sensation and Working-Class Entertainment — page 198: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

cu, xiv.) HEXTRAVASATION OF WATER, ETC. 181 In order to estimate the contraction of the globe as a whole, which would arise from the extravasation of a certain quantity of water-substance from beneath the crust, we may proceed as follows. ° Suppose s to be the volume of the water-substance in ques- tion mingled with the rocky matter in the magma, and we will assume that when sg is extravasated the volume of the magma is diminished by s. This assumption is most favourable to the diminution of volume, but excessive; because, if the rocky matter of the magma, be in solution under pressure along with the superheated water, the volume of the combined substances is probably less than what the sum of the two volumes would be separately. Let » be the density of the water substance. Then ps is its mass. Now if this goes to form a layer of water of depth & and density 1 over the whole globe, the mass of such a layer will be 4arr’6’ very nearly, because 6 is very small compared with r. Hence | ps = 4rd’. Now the radius of the sphere before the extravasation of this water substance having been r+ er, the diminution of volume caused thereby will be $7 {(r+ ery —r*t,and this must be equal to s; that is to 3 , ‘ ~=r(54 e+ e) ph MS a, _ r(¢ +e + e) 5 e" Putting the area of the ocean at 145 millions of miles, the area of the globe being 197 millions, it 1s obvious that , 145 6 = = 797 © § being the mean depth of the ocean, and = 3'5 miles, GONG oOo SS (CO)