Penny Blood: Serial Sensation and Working-Class Entertainment — page 50: what you’re looking at

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

cu. 11.] INTERNAL DENSITIES AND PRESSURES. 33 which at the centre, where n=0, becomes unity. Hence the pressure at the centre 1s gpa sin 2ga (tan ga— qa) 20 * BD. ae) (Qa~ mn ga). To calculate the pressure in pounds on the square foot, we observe that gp is the weight of a cubic foot of rock at the surface, or gp = 2°75 x weight of a cubic foot of water ; = 171 875 pounds. Archdeacon Pratt has found for the mean values of the axes of the > Spherord corrected for local attraction’, a = 20926184 feet, 8 = 20855304 feet. If we define the mean sphere as one of equal volume with the spheroid, then a’ = a'B, and “ @=20,902,520 feet; which we will take to be the value of the mean radius. Then, with the values of ga already given’, we obtain for the pressure upon a square foot at the earth’s centre 6,351,810,000 pounds. Reducing this to atmospheres at 14°7 pounds per square inch, the fluid pressure at the centre of the earth will be found to be 3,000,660 atmospheres. This, as will be observed, considerably exceeds Walters- hausen’s estimate’. 1 Pratt’s ‘* Figure of Earth,” 4th ed. Art. 173, 2 p. 30. 3 See Table, p. 31. GONG oOo SS (CO)