46 Lieut. Beaufoy's Astronomical Observations, 1S26. 



therefore, sufficient evidence perhaps to say that the crystals 

 of Haytorite are pseudomorphic ofHumboldtite. The repo^ 

 sitories of the two substances seem to be different : for besides 

 the ah'eady known localities ofHumboldtite, — the Seiser alp in 

 the Tyrol, andSalisbury-craig near Edinburgh, — I know only 

 of another, which is Utoe in Sweden, where, to judge by the 

 specimen in Mr. Heuland's collection, it occurs in macled cry- 

 stals, and accompanied by apophyllite, carbonate oflime, sul- 

 phate of barytes, and bitumen. 



In conclusion it may be said, that if the reasons for supposing 

 the crystals of Haytorite to be pseudomorphic appear conclu- 

 sive, thei'e is some not unreasonable ground to think they may 

 owe their form to Humboldtite, but have been modelled upon 

 crystals of that substance larger and of a different variety than 

 those which have been met with hitherto; or otherwise they 

 must be considered as pseudomorphic crystals of an unknown 

 species. 



XIV. Astronomical Observations, 1826. By Lieut. Beaufoy, 



R. N.- 



Bushey Heath, near Stanraore. 



T ATITUDE 51° 37' 44" 3 North. Longitude West in 



-*-' time 1' 20" 93. 



Nov. 29, Solar Eclipse. Beginning 21"^ 46' 04'' M. T. Bushey. 



End ... 23"^ 58' 19" M. T. Bushey. 



No spots were visible on the sun's disc. The edge of the 



moon uneven, and her horns blunted. 



Dec. 3. An occultation of a"! ,,„v ... .„„ ^ c-j t>- 



1, ^ , ^, >22'' 44' 40" 6 Sid. Imie. 



small star by the moon ... J 



extent it may be said, that the smaller the difl'erence between the mea- 

 surements of two crystals, if well established, the greater is the difficnlty to 

 refer them to the same primitive form. If therefore the difference which 

 Mr. Phillips and myself have found should prove to be correct, it would be 

 most likely an insurmountable objection to the re-union of Humboldtite 

 with Datholite. There is not a much greater difference between the cry- 

 stals of Cleavelandite and Felspar, than there would be between those of 

 these two substances. There is still anotlier way to compare the crystals 

 of Humboldtite with those of Datholite : it is by supposing that the planes M 

 of the first correspond to the planes i of the second (see Phillips's figures) ; 

 for according to Mr. Phillips they measure exactly the same angles j but 

 then a difficulty of the same order as the one above would be raised, with 

 respect to the identity of the faces e- of Humboldtite and a- of Datholite. 



XV. A List 



