30:2 APPENDIX. 



own observations, to which I am happy to add the following, 

 kindly furnished by Mr. Glaisher. 



" In regard to the subject of snow crystals, the severe period 

 at the commencement of this year threw much additional light, 

 and satisfactorily established that, with the exception of di- 

 minished size, the snow crystals of our latitudes are as com- 



Mt 



plex as those of colder regions, to which formerly they were 

 supposed to be confined, and in consequence were designated 

 Polar snow by ancient writers, of whom Aristotle and 

 Descartes were among the first. This supposition, indepen- 

 dently of the evidence furnished by the correspondence of my 

 own drawings and those of Dr. Scoresby and Sir Edward 

 Belcher, seems to be pretty nearly disproved by the prevalence 

 of one common character existing in all that I have noticed 

 during the last two winters, when they have constituted 110 

 unimportant part of my meteorological investigations. 



" The base of each figure that I examined was either a star 

 of six radii or a plane hexagon, the accessions to the original 

 figure being composed of spiculte, prisms, rhomboids, or hexa- 

 gons, aggregated around the principal radii at an angle of GO , 

 in strict accordance with the law applying to the crystalliza- 

 tion of water. The size of these beautiful formations might 

 be considered to vary from an almost infinitesimal speck to 

 0'5 inch in diameter, (VI and (V2 being the most prevalent 

 sizes that I observed. 



" To the naked eye their general effect differed considerably, 

 in some instances being perfectly arborescent and fern-like in 

 character, in others as produced by the interlacing of spiculse 

 or prisms ; these last might be considered to belong rather 

 to the lower temperatures than the former, which had some- 

 what an affinity to the beautiful incrustations that we wit- 

 ness on glass during frosty weather. Of the greater number 

 that I observed the radii were of even length, and the in- 

 crustations on them similar; but some I recorded of which 

 three long alternated with three short radii, the former richly 

 laden with secondary and tertiary formations, the latter slen- 

 der and but slightly laden. Such figures were more frequently 



