This specimen is described as a fine, even-grained typical granite containing both biotite and muscovite with quartz and feldspar. Its specific gravity is 2.672. It had a crushing strength of 17,254 lbs. per square inch, weight applied perpendicular to the rift, and 19,957 lbs. parallel to rift.

Its crushing strength was 25,100 lbs. per square inch.

Its mineral constituents are principally quartz, hornblende, and feldspar. The stone is very hard and capable of receiving a high

polish. Its crushing strength was found by Gillmore to be 17,750 lbs. per square inch, and its specific gravity 2.669.

This stone has a shearing strength of 2419 lbs. per square inch and a coefficient of expansion of 0.00000461 per inch. Granite from Millbridge had a coefficient of expansion of 0.000004 between 32° and 212° F.

The total value of the granite output of the United States for the years 1896 and 1897 is $7,944,994 and $8,905,075 respectively. Of this amount nearly one-half was furnished by the States of Massachusetts, Maine and Vermont. The value of the paving-blocks for the same years was $1,231,736 and $1,140,417. In 1896 Maine furnished $344,101 worth, Massachusetts $324,784, and Georgia $94,390; while in 1897 Georgia supplied $295,005 worth, Massachusetts $243,750, and Maine $172,637. This great falling off in values in New England is attributable to the increased use of asphalt for pavements in cities which in former years drew largely from the New England quarries. This use of asphalt not only decreased the quantity of granite used, but also the value per thousand of the blocks themselves.

VALUE OF GRANITE PRODUCT 1890 To 1897.

This stone had a crushing strength of 34,920 lbs. per square inch and a specific gravity of 2.965.

From the above and microscopic examinations the mineral constituents were found to be plagioclase, feldspar, pyroxene, and hornblende, with 4.56 per cent of magnetite or magnetic iron. This is a stone similar to that forming the Palisades of the Hudson in New Jersey.

RESULTS OF TESTS MADE OF CRUSHING STRENGTHS OF DIFFERENT GRANITES.

Sand is formed by the decomposition or disintegration of rocks. It is a common occurrence to find pockets of sand in beds of earth or limestone. These are the result of boulders being surrounded

when these deposits of clay or stone were first made. Long afterwards the boulders decayed, and in their places are discovered pockets of sand. Its composition depends upon the minerals contained in the original rocks.

When large deposits of stone decay, the particles of quartz, being indestructible, are borne away principally by two agencies, water and the winds. At this time the different products are often separated and the quartz, being heavier than the decomposed mineral, is kept. by itself, as in the case of the sands of the seashore and those of a desert.

Large grains are as a rule affected more than small ones. Sea sands are less sharp than those of rivers and lakes, on account of the constant action of the waves and tides; while those of a desert or any place subject to the action of the winds are most rounded of all. It is only in desert sands that the smallest grains show any great effect of attrition.

Sandstone is formed by grains of sand being deposited in beds by some agency and afterwards compacted. The sand proper is almost all quartz, as this mineral is indestructible from the ordinary action of the elements, while the cementing portion of the original rock has generally been decomposed and a new substance formed. The solidification of the stone is caused by great pressure, partial solution, fusion of some of its own parts, or by the infiltration of some cementing material, such as silica lime, or the oxides of iron. It is generally found in layers of variable thickness separated from each other by some softer material. The thickness of these layers probably depends upon the time one force acted continuously upon the sand, the softer deposits being made during the intervening period.

The texture of the stone varies according to the sizes of the sand-grains, some being so fine as to be barely discernible, while others are very coarse, with every gradation between them. Mica and feldspar are sometimes ingredients, and upon the composition, as well as the cementing material with which it is held together, depends its value as stone.

Sandstones are of many colors, the most common, however, being gray, yellow, and red. These colors are determined by the different combinations of iron; the red being due to peroxides, and