GEOLOGY. 317 



It is supposed that this number would have been greatly augmented 

 had the shooting parties gone into the interior of the country. 



Another interesting table has been published, showing the monthly 

 mean height of the barometer and temperature of the air on board 

 the Investigator, from August, 1850, to March, 1853 : from which the 

 following yearly abstract is drawn. 



Barometer. 1SSO. 1851. 1852. 1853. 



Maximum 33-650 30-750 31-000 30-726 



Minimum 

 Mean . 



.Air. 



Maximum 

 Minimum 

 Mean . 



29-160 .... 29-030 .... 28970 .... 29-180 



29-828 .... 29-934 .... 29906 .... 29.960 



+5 .... +52 .... +52 .... +17 



40 51 52 65 



4-65 .... +1-58 .... +0-05 .... 3592 



STRENGTH AND DENSITY OF BUILDING STONE. 



By a series of experiments recently tried in Washington, under the 

 direction of the Ordnance Board, the specific gravity of various sand- 

 stones presented, averaged 1,929 the best Quincy granite, or to 

 speak properly, Sienite, 2.648, and the Malone sandstone, 2,591. 



The report of the examining officers further states 



1st That the sandstone of the capitol broke under a pressure, per 

 square inch, of 5,245 Ibs. 



2d Several of the marbles tested broke under pressures varying 

 from 7,000 to 10,000 Ibs. 



3d The compact red sandstone, of which the Smithsonian Insti- 

 tute is built, broke under 9,518 Ibs. 



4th The granite, or blue micaceous rocks employed for the new 

 foundations, broke (as the average of 7 samples) under 15,603 Ibs. 



6th The Malone sandstone, 24,105 Ibs. 



7th The most compact Sienite from Quincy, 29,220 Ibs. 



It should be mentioned that the various sandstones were tested in 

 the weakest position with the lines of stratification perpendicular 

 to the horizon, as such is the way that they are usually employed in 

 building. The marbles and granites were tested in an exactly oppo- 

 site position. 



RESEARCHES ON CRYSTALLIZATION. 



M. Lavalle has recently presented to the French Academy a memoir 

 narrating some remarkable phenomena discovered, and patiently ob- 

 served by him. All bodies, whose composition is clearly defined, have 

 a tendency to crystallize ; in other words, when they take the solid 

 state slowly, their last particles, in grouping themselves, each after the 

 other, are so disposed as to form a mass, which .the mind successively 

 decomposes into plane layers, into rectilinear files, and into elementary 

 particles. As these are disposed parallel to each other, and at equal 

 distances, to be arranged in files, so the layers are formed by the 



