Meteor seen at Rochester, N. America. 647 



The northernmost coal of Yorkshire rises northward be- 

 neath a cover of the same limestone, and ranges e. and w. ; 

 forming, with its south-western boundary, a westerly pointed 

 figure, widening and deepening south-eastward. 



The question of an east or northeasterly continuation of the 

 coal-measures can only be entertained at the easterly end of 

 the east and west range, before-mentioned ; but we must pre- 

 viously turn to other places, to see, by analogy, how far any 

 subterraneous deflection in the range of the coal-measures may 

 be thereabout expected. 



Along the westerly edge of the coal-measures, both in York- 

 shire and Derbyshire, there are well-known irregularities 

 occasioned by elevations and depressions across the general 

 range of the series, causing sinuosities in the marginal edges 

 of the coalfields. The lands eastward, over the ridges, con- 

 tract, and those westward, in the hollows, expand the width of 

 the coal-measures ; so that the first rise in the north side of the 

 Dun causes a vacant space between Sheffield and Chapel- 

 town ; and the second rise south of Sheffield, and in Derby- 

 shire, causes a vacant space in the productive coal-measures 

 between the high part of Sheffield Park and Coal Aston ; and 

 in the hollow between these two ridges the coal is thrown back 

 under Sheffield. But there is a greater westward receding in 

 the Dronfield trough, one side of which, rising to the north, 

 causes a long east and west range through Coal Aston. 



We have therefore, north and south of the Dun, two east and 

 west ranging lines of the coal-measures (similar to, but much 

 shorter than, that on the north side of the Yorkshire coal- 

 field), from which two east and west ranging lines the coal is 

 known, in both cases, to return and resume its regular course. 



That in Derbyshire, from Eckington to Stubly, is several 

 miles in extent: but it is not from the magnitude, but from the 

 similarity, of these irregularities that we may infer the proba- 

 bility of the coal-measures, in class of the most northerly 

 works in Yorkshire, continuing easterly, or resuming a north 

 or north-easterly range, though it may be at a great distance be- 

 neath their unconformably covering strata. — William Smith. 

 Scarborough, Sept. 29. 18 '57. 



Notice of' a Meteor, in a Letter to Professor Silliman. — 

 Rochester (North America), August 7. 1837. You have pro- 

 bably seen some account of the meteor that appeared in this 

 region on Wednesday, the 5th ult. I had the satisfaction of 

 seeing it myself as I was walking in the street betwixt seven 

 and eight o'clock in the evening. It first made its appear- 

 ance from behind a dark cloud, a little to the south-west of 

 this place, and flashed along through the heavens with great 



