120 Mr Haidinger's account of' the Specific Gravity 



from which we obtain, 



Eq. Temp.= =r- Eq, Terap.=* — ?~ 



^ r cos. L. ^ v cos.2 L. 



Hawaii, - 79°.67 82°.40 



Mean of both, 81° .04 



Hence, it appears that the equatorial temperature is still be- 

 low 81 J°. 



From these results we think there is reason to conclude, 

 that the measure of the equatorial temperature, as given by 

 Humboldt, is the best, taken as a general result, and that there 

 is no occasion to modify any of the formulae which have been 

 founded upon it, for determining the distribution of tempera- 

 ture in different latitudes. 



Art. XVI. — On the Specific Gravity of several Minerals. 

 By W. Haidingee, Esq. F. It. S. E. (Concluded from 

 Vol. III. p. 246.) 



Ohder VII. Gem. 



1. Gahnite, a crystal 4.232 



2. Corundum, a red semi-transparent crystal, 3.909 



3. Corundum, a brown nearly opaque prism, the adamantine spar 



of Werner, 3.921 



4. Corundum, green, translucent fragments of crystals ; faces of 

 composition distinct, giving the appearance of cleavage in the direc- 

 tion of the fundamental rhombohedron, 3.949 



5. Corundum, a white transparent crystal, 3.965 



6. Corundum, green, translucent fragments of crystals, with a 

 small conchoidal fracture, 3.966 



7. Corundum, a blue transparent crystal, 3.979 



8. Topaz, a large crystal from Mukla, 3.499 



9. Topaz, from Altenberg in Saxony, (Pycnite,) 3.494 



10. Euclase, a single crystal, 3.098 



11. Cordierite, transparent, cut and polished, 2.583 



12. Rock-crystal, found along with sapphire, in Ceylon, 2.690 



13. Opal-jasper, cream-yellow, without lustre, and imbibing wa- 

 ter, from Bohemia, 1.974 



14. Opal-jasper, pale brown, with a faint lustre, and imbibing 

 water, from Bohemia, 1 .982 



15. Opal-jasper, blood-red and brownish-red tints intermixed, 



from Candia, 2.060 



16. Opal-jasper, of an ash-grey colour, from Gleichenberg, in 

 Stiria, , 2.075 



