seven teeth ; and with the most liberal allowance for decrease of size in 
___. the other four, the whole of the seven could not have measured less than 
16 or 18 inches, which is about one half larger than in the P. magnum. 
Vertical view of the posterior tooth, belonging to the lower jaw of Mr. Prout’s 
BBs Ne Palzotherium—natural size. 
a 7. Relative Quantities of Land and Water on the Surface of the 
Earth ; by Prof. S. P. Rieaup, (Trans. Camb. Phil. Soc., vi, 289, 
1887.) Prof. Rigaud obtained his results by cutting up the map paper 
of a three feet globe (one of Mr. Addison’s), separating thus the land 
from 1e water, and weighing each parcel. Every precaution was 
taken to ensure accuracy, and full confidence may be placed, it is be- 
lieved, in his results, excepting of course such errors as necessarily 
arise from ignorance of regions yet unexplored by man. 
_ This mode of determining the proportion of land and water was used 
by Dr. Halley in 1698; and afterwards for the whole globe by Dr. 
Long, as published in his Astronomy, (1742,) Art. 580. 
_ The following are some of the results arrived at by him. The sphere 
'S Supposed to be divided into 1000 parts, and out of them the ratio of 
and to water in the— ina alata ' 
: , : ‘Water. ~ .° 
Whole ‘sphere; 2 265.9233. . .734-0762 of 100: 276" 
Northern hemisphere, ,--«:197-2153.. .802°7846 “ 100: 154 
Southern hemisphere, .  68°7080...431:2916 “ 100: 628 
Torrid'zone, 98-7171... 300-0818 * 100: 304 
Notth polar citele;> . . 18-0268... 234487 “ 100: 139 
N rl temperate zone, i 1266308 . . .192:5247 “ 100: 105 
The late discoveries in the Lennie region will require a correction of the 
to here given for the whole sphere. Dr. Long obtained for this ratio, omitting 
© Polar circles, the ratio of 100 to 281. es j 
2a Saeed 
