382 Mr. T. S. Davies on Geometry and Geometers, 



I have this day received the following additional accounts 

 of this meteor from Mr. Fasel, who with the Rev. J. B. Reade 

 has revisited the spot from which he saw the meteor, and 

 found by compass that the place occupied by the meteor when 

 first seen was due magnetic north (about 7° west of true 

 north). Just previously to this time Mr. Fasel was walking 

 with his face towards the west, when the bursting of the me- 

 teor caused him to turn his head towards the north. He 

 then went home, made a diagram in his journal (a copy of 

 which he has forwarded to me), and described it as a very 

 brilliant meteor of the size of a star of the first magnitude, 

 and it left a long train of red light. 



From Mr. Jones's account, the meteor was first seen 



At an altitude of. 13 and in azimuth 68 E. of N. 



Its altitude at tlie next observation was 27 and its azimutlj 89 E. of S. 



49 ... 63E. ofS. 



56 ... 45E. ofS. 



Its altitude at explosion was 60 ... 8 W. ofS. 



From Mr. Fasel's account, the meteor was first seen at an 

 altitude of 30°, and in azimuth 7° W. of N., and its altitude 

 at explosion was 38°, in azimuth 59° W, of N. 



The path of the meteor seems to have been from E.N.E. 

 to W.S.W., and was contrary to the order of planetary 

 motion. 



The intersections of the azimuths at explosion indicates 

 that the meteor at this time was vertical over a spot at about 

 fifteen miles from Montgomery, and north-east of it. Its 

 distance from the earth at this time was about eighty miles. 



Blackheath, April 22, 1850. 



XLVIII. Geometry and Geometers. 

 Collected by T. S. Davies, Esq., F.B.S. and F.S.A.^ 



No. V. 



THE mathematical collections of Pappus have an enduring 

 interest to the geometer ; but without question, the short 

 notice respecting the Porisms of Euclid (in the preface to his 

 seventh book) is the most interesting part of the whole work. 

 It is unknown what MSS. were used by Commandine in 

 making his translation; and all that have been since discovered 

 are of comparatively modern dates. From some remarkable 

 coincidences, there is reason to believe that the MS. of Com- 

 mandine was of the same period as some of these : — one of 

 which coincidences is, the absence of a figure alike from all 

 known codices and from Commandine's translation. They 

 are all alike defective in not even verbally describing this 



♦ Communicated by the Author. 



