32 Remarks on the Density 



got out of a walk. The mule's pace had knocked him up. Be- 

 gan to calculate on a night in the savannah. The moon had 

 forsaken us before we reached a ravine, across which with ex- 

 treme difficulty we groped our way ; at one place obliged to 

 dismount. The passage took full ten minutes. To my great 

 satisfaction, the animal carried me to Angostura, by a little 

 before eleven o'clock. Had eaten nothing since morning, and at 

 that late hour could procure only a little bread and cheese, and 

 some maize for our beasts. My new purchase promised well ; 

 eighteen leagues for the first day's work was no bad beginning ; 

 his figure fine and paces good, but he soon after died of a dis- 

 ease in the throat, during the subsequent illness of myself and 

 my boy. Our baggage did not come in till the following evening. 

 The soldier's poor mare so knocked up, that neither force nor 

 persuasion could make her quit the door, where she remained 

 a full week, and then contrived to find her way to the savannah. 



Art. II. Remarks on Laplace's latest Computation of the 

 Density and Figure of the Earth. 



It cannot but be highly flattering to any native of this country, 

 to have his suggestions on an astronomical subject admitted and 

 adopted by the Marquis de Laplace : but in applying the theory 

 of compressibility to the internal structure of the earth, it ap- 

 pears that this illusti'ious mathematician has deviated somewhat 

 too widely from the physical conditions of the problem ; partly in 

 order to obtain a convenient and elegant formula for expressing 

 the results, and partly, perhaps, because he was not acquainted 

 with all the experiments, by which these conditions are deter- 

 mined. 



Instead of proceeding with the calculation upon the analogy of 

 the well knownlaw of the compression of aeriform fluids, which ex- 

 hibit an elasticity simply proportional to their density, M. Laplace 

 has at once assumed that the elasticity of a solid body is propor- 

 tional to the square of the density. Now there seems to be no 

 very good reason why we should suppose the elasticity to in- 

 crease more rapidly, with the density, in the case of solids or 

 liquids than in that of elastic fluids; and it would be very dif- 



