OBSERVATIONS OF LUMINOUS METEOES. 299 



and then edgewise, to the prescribed depth into the ground, for which, 

 fifty blows were found to be necessary in the first, and twenty blows in 

 the latter form of the experiment. A mean of these may fairly be 

 adopted as affording a pretty accurate determination of the aerolite's real 

 energy of impact and of its work of penetration through the solid earth. 

 This^measured quantity was 9,307 ft.-lbs., and taking the stone's weight 

 as 31bs. 8J,ozs. when it fell, it is easy to infer from this that the actual 

 velocity of fall with which the stone struck the ground must have been 

 412ft. per second. As it would acquire this velocity by falling freely 

 through 440 fathoms, or half-a-mile, while in falling freely forty miles 

 from the highest regions of the atmosphere to the earth, it would reach 

 the earth's surface with a velocity nine times as great as that actually 

 observed, it is sufficiently clear how little of the original planetary speed 

 ■with which it entered the atmosphere can have remained over to affect in 

 any marked degree either the terminal velocity or the verticality of its fall. 

 The immense opposition and resistance which the air offers to the 

 intruder's passage, even through its upper strata, is, in fact, evident from 

 the deep erosions, by heat and attrition together, which the aerolite's front 

 surface has received. 



A model, hand-moulded in clay, and then cast in plaster, of the 

 meteorite, easil}^ coloured to imitate it, with brushed black-lead on the 

 furrowed face, and with dull brown paint upon the back, was made by Pro- 

 fessor Herschel on the arrival of the stone at Newcastle, where the aerolite 

 was publicly exhibited for a short time. A copy of the model was sent to 

 the British Museum, and was there shown in the newly opened galleries 

 of the Mineralogical Department of the Natural History Collection at 

 South Kensington. The stooe itself was also beautifally photographed in 

 several positions by Mr. Gould, the artist-photographer of Sir William 

 Armstrong's Ordnance Works in Newcastle-on-Tyne, and copies of these 

 photographs and of the model were distributed to several quarters, one, at 

 Dr. Brezina's request, being sent with a small specimen of the stone to the 

 Vienna Imperial Mineralogical Museum. 



Calculated from the water- displacement of the model, the stone's 

 specific gravity is 3'15. But this estimate may be a little underrated, 

 from a small exaggeration of the marginal outline, perhaps not entirely 

 counteracted by opposite errors of the thickness of the model imitation. 

 Approached to a silk-suspended magnetised needle the meteorite attracts 

 it in all positions slightly, showing a uniform distribution through it of a 

 sensible quantity of metallic iron, . which, however, usually imparts to 

 ordinary stony aerolites a rather higher average specific gravity than 

 that above concluded from the model's water-displacement. 



Having decided upon its appearance at York in the approaching exhi- 

 bition of objects of scientific interest, formed to assist the British Asso- 

 ciation in celebrating in that city its fiftieth annual meeting, the Board of 

 Directors of the North-Eastern Railway Company appointed a Committee 

 to arrange for the immediate section and analysis of the aerolite. An 

 angle was sawn oS" from the back by a skilled lapidary, weighing about 

 50 grammes, and large enough to afford a thin microscopic section, which 

 was produced ; and the resulting fragments of the operation were, after 

 some unavoidable delays, placed with the microscopic section in the hands 

 of the Keeper, Mr. Fletcher, and the mineralogists, Dr. Walter Flight 

 and Mr. T. Davies, of the Mineralogical Department of the British 

 Miisenm, as presents from its possessors of original fragments of the 



