HILL: GEOLOGY OF JAMAICA. 19 
The Mountains of the Interior. — These comprise the Blue Mountain 
Ridge, which dominates the topography of the eastern third of the 
island, and certain peculiar isolated summits to tho west of the Blue 
Mountains proper, such as Jerusalem Mountain, Westmoreland, and 
the Clarendon (Bull Head) Mountains of Clarendon Parish. The 
isolated groups occur as limited inliers, surrounded and overlooked by 
hills of the limestone plateau. 
The Blue Mountains form a sinuous divide with many bifurcating 
branches. They extend one third the length of the island, from near 
the eastern point towards Port Maria, and have a trend of north of west, 
parallel to the truncated northeast coast of the island. In general, this 
ridge marks the boundary between the eastern parishes of the north 
side (Portland and St. Mary) and those of the south (St. Thomas, St. 
Andrew, and St. Catherine). It presents a serrated crest line with 
radiating laterals whose summits culminate near tho centre of the ridge 
in the Blue Mountain Peaks (alt. 7,360 feot).! West of these peaks the 
altitudes gradually decrease until they become lower than those of the 
surrounding limestone hills beneath which the mountain structure was 
buried in ancient timos. Everywhere the ridge and numerous laterals 
Which project from it at right angles present the profile of an inverted 
letter V, thus A. Its configuration is singularly free from benches, 
Mesa tops, or vertical escarpments, the last seldom occurring except as 
the bluffs immediately adjacent to the present stream beds. 
Imagination pictures no more exquisito scenery than that which 
attends the ascent of Blue Mountain Peak. With increasing altitude 
Panorama after panorama of tropical laudscape unfolds in rapid succes- 
Sion. At Gordontown, nine miles north of Kingston, where the interior 
Margin of the Liguanea Plain meets the mountain front, the ascent 
through the red-colored cliffs of the Hope River Canyon begins, which 
here, at an altitude of 900 feet, debouches into the gravel plain through 
a boca, A thousand feet above, the white buildings of Neweastle Bar- 
racks look like doves upon a housetop, yet we climb so far above 
them that they seem like toy houses below. At 2,000 feet the Plain 
of Liguanea with its city and villages and the shipping of Kingston 
Harbor, grow smaller and smaller, and finally appear like a diminutive 
Plaza below us. Sometimes our path clings to the side of steep de- 
elivities, with an apparently endless slope above and a bottomless chasm 
below, Again, it follows a knife edge from which we can see beyond, 
9n both sides of the island, the waters of the Caribbean, so distant and 
1 Altitudes given in this report are mostly from the Jamaican surveys. 
