242 FRANK D. ADAMS 



miles. Mount Johnson and Brome mountain lie on a line paral- 

 lel to them, but a short distance to the south, Rougemont being 

 the nearest neighbor to Mount Johnson and Brome mountain 

 being immediately south of Shefford. It is highly probable, in 

 view of this distribution, that these ancient volcanic mountains 

 are, as is usual in such occurrences, arranged along some line or 

 lines of weakness or deep-seated fracture. The "pretty nearly 

 straight line" referred to by Logan on which the first six moun- 

 tains of the group are situated must be considered either as a 

 single line with a rather sharp curve in the middle, or as made 

 up of two shorter straight lines, each with three mountains, 

 which diverge from one another at an angle of about 30", Mon- 

 tarville being located at the point of intersection. Mount John- 

 son and Brome mountain might then be considered as situated 

 on short subsidiary fractures. 



Brome and Shefford, however, which are the two largest 

 mountains of the series and which are only separated by a dis- 

 tance of a little over two miles, are probably connected at no 

 great depth below the surface, forming in reality one large mass, 

 while Mount Johnson, like the similar volcanic necks of Fife and 

 Wiirtemberg, may have no direct connection with any line of 

 fracture. It must be noted, as mentioned by Dresser,^ that 

 while six of these mountains rise from the horizontal strata of 

 the plam, the two most easterly members of the group, named 

 Shefford and Brome, while still to the west of the axis of the 

 range, lie well within the folded belt of the Appalachians, 

 though, owing to the extensive denudation from which the 

 region has suffered, this folding has had but little influence on 

 the local topography. 



No collective name has hitherto been proposed for this 

 remarkable group of hills. ^ From their intimate geological 



^"On the Petrography of Shefford Mountain," Amer. GeoL, October, 1901. 



'The only instances in which these hills have been referred to as a geographical 

 unit are, so far as can be ascertained, in a paper by Sterry Hunt entitled " On Some 

 Igneous Rocks of Canada," Am. Jour. Science, March, i860, where they are called the 

 Montreal group ; and by Elie de Beaumont, who in a late edition of his Syslemes des 

 Montagms included these hills as one of his systems, under the name of the "Systeme 

 de Montreal." See Prestwich, Geology, Chemical, Physical and Stratigraphical, VoL 

 I, p. 294. 



