Abstract
WE are again indebted to the early sheets of Harper's Weekly for the following:—At a late meeting of the Boston Society of Natural History a communication was presented by Count Pourtales in reference to the character of the sea bottom off the coast of the United States, south of Cape Hatteras, and based upon the researches of the Coast Survey. According to his statement, the principal constituent of the coast is silicious sand from the coastline to about the line of one hundred fathoms—a limit which coincides nearly with the inner edge of the Gulf Stream throughout the greater part of its course. Outsideof this line is a whitish calcareous mud, containing globigerina, and extending probably over the greater part of the ocean. South of the Vineyard Islands, and to the eastern end of Long Island, the silicious sand is replaced by a kind of bluish mud, known as the Block Island soundings. A similar mud is found off Sandy Hook in a range of depressions known as mud holes, which form a leading mark by which to find the port of New York in thick weather. A few rocky patches are found east of the neighbourhood of New York, and a rocky bottom occurs, sparingly, near Cape Fear; but otherwise the sand is pretty uniform, varying only in the size of its grain. On the inner edge of the Gulf Stream there is a deposit of greensand composed of the cast-orl foraminifera.—According to late advices from Florida, Mr. N. H. Bishop, whose visit to that State in the interest of natural history we have already referred to, has started off in his yacht on a cruise down the coast for the purpose of making collections of Florida birds, &c. He hopes to penetrate into the Everglades and prosecute some inquiries in regard to certain species of birds said to occur there, and no where else in Florida.—We regret to have to record the death, at St. Paul, Minnesota, on the 13th of December last, of Prof. William Chauvenet, formerly Chancellor of Washington University, St. Louis. This gentleman has long been known in American scientific circles for his attainment as a mathematician and astronomer; and the various works published by him have occupied a high position as text-books and manuals of instruction. For a time connected with the Naval Academy at Annapolis, he was subsequently elected Professor of Astronomy and Mathematics in Washington University, St. Louis, afterwards becoming Chancellor, and remaining there until 1869. His death occurred in consequence of exhaustion of the nervous powers at the age of a little over fifty.—We regret to learn that in the course of a disastrous fire at Springfield, Illinois, on the 25th of February, the collection of the Geological Survey of the State of Illinois was in large part either destroyed or greatly injured, especially the fossil plants. This loss is the more severe, as the collection in question contained one of the finest series of Carboniferous fossils in the country, and embraced a large number of types of new species described by Messrs. Worthen and Meek. This should be a warning to all who have charge of valuable natural history collections, to give themselves no rest until their treasures are secured in fire-proof buildings.—We recently called attention to the excessive degree of cold to which meteorological observers on Mount Washington have been subjected during the present winter. Since then still greater inclemency has been recorded, during which the thermometer was fifty degrees below zero, while the wind had a velocity of one hundred miles an hour.—We have already, in a previous number, referred to the examination of a locality in California, by Prof. Marsh's exploring party, where numerous fossil trees had previously been discovered; and we learn that a detailed report may be looked for in the April number of the Journal of Science. The region in question is situated on a high, rocky ridge in Napa County, California, near Calistoga Hot Springs, and about ten miles from the summit of Mount St. Helena. The ridge itself belongs to the Coast Range series, and forms the division between the Napa and Santa Kosa valleys. It is about two thousand feet in height, and is composed of metamorphic rock of the cretaceous period, overlain unconformably by later tertiary strata, consisting of light-coloured, coarse sandstone, and beds of stratified volcanic ashes. A careful examination showed that the trees on the-surface of the ground had been weathered out of the volcanic tufa and sandstone, and consequently were of the Tertiary age; and also that there remained still embedded in the volcanic tufa, &c., an extensive forest of very large trees, stretching over a great area. Some of the trees were of great size, a portion of one having been traced for a length of sixty-three feet, with a diameter of seven feet near its smaller end. Another tree indicated an original diameter of not less than twelve feet. All were prostrate, and had apparently been thrown down by the volcanic current which covered them, Many were much decayed internally and worm-eaten before they were buried. All of the wood was silicified, probably by means of hot alkaline waters containing silica in solution—a frequent result of volcanic action. A careful examination of the wood obtained at this locality showed no essential difference in structure from that of the modern redwoods of California (of the genus Sequoia). No other fossils were met with, which rendered it somewhat difficult to fix the precise epoch; but it is considered probable by the Professor that the trees belonged to the Pliocene period. The origin of the volcanic material which covered the forest could not be ascertained, although it was supposed to have been derived from Mount St. Helena, which is the nearest volcanic peak.
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American Notes . Nature 3, 408 (1871). https://doi.org/10.1038/003408a0
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DOI: https://doi.org/10.1038/003408a0