Page:The American Cyclopædia (1879) Volume II.djvu/799

 BOG BOG ORE 7T9 ing out of the account the small ones not ex- ceeding about 800 acres each. The whole amount of bog surface is 2,831,000 acres, nearly all of which forms one almost connected mass. The great bog of Allen, E. of the Shan- non, extends 50 m. in length by 2 to 3 in breadth. This is divided by occasional high lands into several bogs. They all consist of peat, averaging about 25 ft. in thickness, never less than 12 nor more than 42. The upper 10 ft. is composed of a mass of the fibres of the mosses, more or less decomposed, and a light turf of blackish brown color underlies this, in which the fibres of moss may still be perceived. This variety may extend 10 ft. deeper. " At a greater depth the fibres of vegetable matter cease to be visible, the color of the turf be- comes blacker, and the substance much more compact, its properties as fuel more valuable, and gradually increasing in the degree of blackness and compactness proportionate to its deptli ; near the bottom of the bog it forms a black mass, which when dry has a strong re- semblance to pitch or bituminous coal, having a conchoidal fracture in every direction, with a black, shining lustre, and susceptible of re- ceiving a considerable polish." (Report of surveyors appointed by parliament, 1810.) In England the largest lowland bog is Chat- moss in Lancashire. It is 8m. long, 3 m. in greatest breadth, and contains 7,000 acres. It is a mass of pure vegetable matter, without any mixture of sand, gravel, or other material, from 10 to 30 ft. in depth. It is noted for the engineering difficulties it offered to the passage of the first great English railway. George Stephenson carried the Liverpool and Man- chester railway over it when all other engi- neers considered the task impossible. In the Great Dismal swamp of Virginia and North Carolina, the extent of which is about 40 m. N. and S. and 25 m. E. and W., little true peat appears to be found. The soil is perfectly black, consisting wholly of vegetable matter to the depth of about 15 ft. When dug up and exposed at the surface, it rapidly decomposes. The surface is covered with mosses, reeds, ferns, and aquatic trees and shrubs. The white cedar is abundant as in all our swamps, and they and the tall cypress furnish timber of such value, that the inmost recesses of this tangled morass have been penetrated by canals in search of it. In its central portion the sur- face is found to be 12 ft. higher than the rest, and the general level of the swamp is above that of the adjoining country. Throughout the country, along the seaboard to the gulf of Mexico, swamps of this character are of frequent occurrence. The outer portions are sometimes wooded swamps, while within they present moss-covered heaths, stretching, like the western prairies, further than the eye can see, and dotted occasionally with clumps or little islands of trees. In New England, the northwestern states, and Canada, the bogs furnish genuine peat, and some of those bor- dering the great lakes are of great extent. Over one of these the traveller is carried upon the Great Western railroad in Canada, between Chatham and Lake St. Clair. Upon Long Island, near New York city, the bogs present a marked feature along the sandy coast, and their structure was finely exposed in the excavations made for the Brooklyn aqueduct. Here, as elsewhere, they are found to be the repositories of the remains of the mastodon. (See ALLUVIUM, and PEAT.) BOG, a river of Russia. See BUG. BOG ORE, Meadow Ore, or Llmonlte (Gr. /(///>>. meadow), a variety of iron ore, which collects in low places, being washed down in a soluble form in the waters which flow over rocks or sands containing oxide of iron, and precipitated in a solid form as the waters evaporate. It is deposited in the bottoms of ponds as well as swamps, and is found in beds now dry, above the level at which it must originally have been collected, or else these are the product of springs which have now disappeared. The roots of trees appear to have an influence in reducing the peroxide of iron in the sands they come in contact with to the protoxide, by the action of some organic acid. By this action the ore is rendered soluble, and is liable to be precipitated by change to an insoluble salt, in- duced by the influence of the air or other causes. As the waters run among deposits of vegetable matters, and this change slowly takes place, the oxide of iron replaces the woody fibre, retaining in its more solid material the exact form of the branches of trees, of the small twigs, and even of the leaves, with their delicate reticulations. Deposits of bright red peroxide of iron, made up entirely of masses of these forms, which are true ferruginous petrifactions, are worked as iron ore. Exten- sive beds exist at Salisbury and Kent, Conn. ; also in the neighboring towns of Beekman, Fishkill, Dover, and Amenia, N. Y. ; at Rich- mond and Lenox, Mass. ; at Bennington, Monkton, Putney, and Ripton, Vt. ; and at numerous other localities in the United States. The bog ore deposits of Monmouth co., N. J., contain them, among other varieties of the ore. In Piscataquis co., Me., a very remark- able and productive bed of these petrifactions has furnished the supplies of ore to the Katah- din iron works. In the ponds of Plymouth co., Mass., bog ores were found so abundantly, that in the early part of this century 10 small blast furnaces were kept in operation by them. As the supplies became exhausted, more ores of the same class were for a time brought from Egg Harbor, N. J. From the bottoms of the ponds the ore was raised into boats, as oysters are gathered, with long tongs. It was found in lumps of various sizes, some weighing even 500 Ibs. ; but usually it occurs in small, ir- regular-shaped pieces, or in the form of shot. When taken from swamps, the workmen were careful to cover the cavities with loose earth, leaves, bushes, &c., calculating upon another