Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/41

Rh along with that of North Bor-roilva, in the trigonometrical survey of England by Lieut. Col. Mudge. But with these exceptions, no other elevations in the island were ascertained. A barometical measurement which I have made of nearly all the mountains and other remarkable places, has amongst other advantages, enabled me to give a vertical section of the chain throughout its whole extent, which agrees very well with a profile view of the island, taken by Murdoch McKenzie from the Mull of Galloway. The spelling of the Manx names along with their pronunciation and signification has been furnished me by several persons in the isle, well versed in the knowledge of their native language, but I am particularly indebted for it to the Revds. H. Stowell, To Howard, and Wm. Fitz-Simmons.

The length of the island is computed at upwards of thirty English miles, of which about five-sixths are occupied by a large body of mountains stretching from North-East to South-West; its breadth varies from fifteen to eight miles.

The chain spreads or swells out to the northward contracting itself to the southward into the Calf or Barrow of Man, which latter is rather less than six hundred acres in superficial extent, offering thus a gradual slope of fifteen hundred and forty feet from the top of Snei-feldt down to Burchet's house on the southern cliff of the Calf, that is to say, a depression of nearly a quarter of a mile in twenty-one miles taken in a straight direction, or, on a mean average, of about seventy-three feet per mile.

Estimating the mean breadth of the mountainous belt at four miles and a half, and its length at twenty-five, we should have for its superficial extent one hundred and twelve square miles and a half, which when referred to the whole area of the island, on the supposition of its being on a mean average, eleven miles and three