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��1«77, and held the olflce of high sheriff of Herlfonlshire and other important public tniets at various times. He waa treasurer of the Geological society for many years, and honor- ary or corresponding member of many foreign aocieties.

In acientiflc matters, Dr. JelTreys had some- thing of the conservatism natural to a person of his j-ears ; but his opinions, however firmly held, were never expressed with bitterness, and his geniality and hospitality bound to him in ftiendly ties not only scientific men, young and old, but the intelligent and cultured throughout his wide circle of acquaintance. He leaves a son. Mr. Howel Jeffreys, and five daughters, one the wife of Prof. H. N. Moseley of the Challenger expedition. His collection, which for British seas is absolutely unrivalled, pos- sessing many'of the actual types of Turton, Alder, and otiier earlj' British naturalists, and an extremely ricli and largely unique North Atlantic and North Eui-opcan series will form one of the treasures of the National museum at Washington, where a portion of it has al- ready been received. W. H. Dall.

��The history of the undertaking which has resulted in the completion of the Washington monument presents a number of interasting and curious facts ; and the construction of the monument itself, by reason of the magnitude of the structure, has involved some problems of considerable engineering importance.

The early history of the monument may be said to date from 1783, when congress resolved lo erect, wherever the residence of congress should be established, an equestrian statue of Washington; and in 1795, when it was pro- posed to build a monument commemorating the American revolution. Major L'Eufant, the designer of the plan by which the city of Wash- ington is laid out, selected, and Gen. Washing- ton himself approved, the si t« where the finished monument of which we write now stands.

After the failure of these and other similar plans, the next step was taken in 1833, when, nnder the auspices of the Washington national monument society, the aid of the people of the United States was invoked to raise the sum

��required to erect a great national monument, no one to contribute more than one dollar, — a restriction which waa removed in 1845. Money came in slowly ; but by 1847, $87,000 had been raised, and it was determined to make a be- ginning; and, by authority from congress. President Polk deeded the present site to the society. Building was at once commenced, but proceeded slowly ; and in 1854 the society had spent $230,000, and raised the monument to a height of 152 feet above the base.

The original design by Robert Mills included an obelisk faced with white marble, 600 feet high, 55 feet square at the base, and 30 feet square at the top, surrounded at its base by a circular rotunda or colonnade 2.">0 feet in diameter and 100 feet high, in which were to be placed statues of the nation's illustrious dead, with vaults t)encath for the reception of their remains.

The base or foundation masonry was about 80 feet square at the bottom, laid at a depth of hut eight feet below the surface of the ground, and carried up, in steps of about three feet rise, to a height of 23 feet, where it is 58 feet square. The slight depth to which the foundation waa carried was due to the anxiety of the building committee to have something to show for the money expended. It was built of rubble masonry of blue gneiss, the blocks large and of somewhat irregular shapes (nearly as they came from the quarry), laid in a mortar of hydraulic cement and atone lime, the joints and crevices filled and grouted. The shaft of the obelisk waa built hollow, with walls lo feet thick at the base; the well, or hollow interior, being 26 feet square for the whole height then built. The exterior face, to an average depth of sixteen or seventeen inches, was of Maryland marble, usually called alum-stone. The remaining thickness of the walls w,-ks of blue-stone nibble backing, not the best construction for a building of such enormous weight.

To ascertain the kind of earth that would be under the monument, a well w.ia dug, some 25 feet deep, in the immediate vicinity of the site, and the earth particularly extimined. The material was found ver^- compact, requir- ing & pick to break it up, and was pronounced suitable for a stiiicture of the kind. At a depth of twenty feet a solid bed of gravel waa reached, and, six feet lower, water was struck. Before the first course of marble was laid, bench-marks were located from which to test the settlement of the monument. After build- ing to 126 feet in height above the ground. the chairman of the buildbig committee writes.

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