these substances replacing an equivalent of one of its regular components.

When the quantity of oxide of iron is small, and in the state of per-oxide, the felspar is of a red color, and does not undergo any farther alteration from the action of the atmosphere.

When the oxide of iron exists in the state of prot-oxide, or at its lowest stage of oxidation, the felspar is of a green color, and will turn brown by the joint action of the air and water, owing to the per-oxidation of the iron, since we observe a deep brown crust upon the weathered surface of such rocks, known to quarrymen under the figurative name of the "sap," the term originating from an imagined analogy between this decomposed surface and the sap-wood of trees. This crust is apt to separate from the block of stone, and by the expansive action of freezing the water which infiltrates into the rock, the surface is gradually converted into gravel and soil. These remarks apply to the more highly ferruginous sienites. The stone from Quincy, Mass., contains a little prot-oxide of iron, and is observed to change color when kept constantly moist, but it preserves its freshness very well when exposed only to the atmosphere, being moistened but transiently. Thus we observe, that in but few instances, the buildings constructed of this stone become changed in color.

GRANITE QUARRIES.

Maine is pre-eminent for the abundance and excellent quality of her various and beautiful granite rocks, which offer facilities for quarrying and exportation, unequalled by those of any other part of the known world.

However public taste may vary in respect to the shades of color required for architecture, the quarries of Maine, furnishing every variety, will always be able to meet the demand.

Not among the least of the advantages over other states, are the facilities which exist for the ready transportation of the stone to market, since the numerous bays, deep inlets, and estuaries of large navigable rivers, afford ready access to most of the important quarries.

Owing to these uncommon advantages, the granite of Maine is destined to supply the whole Atlantic coast of our country, and the West Indies, for it can be quarried and shipped to any of our large cities at a lower price than any buildingstone can be obtained in their vicinity.

It will be seen by the statistical observations in this report, that many of the Maine quarries can furnish regular dimension stones, of excellent granite, on board ship, for $1,12 per ton, and the expense of transportation to New York is rarely moré than $2,50 per ton. Now there are but few cities where this article will not sell for at least $7 per ton, which will give a profit of $3,38 for each ton of granite.

Since this stone is so beautiful and substantial a material, it is certain that there will be a constantly increasing demand for it, as the population of the country increases, and new buildings are required.

I have not mentioned the high price which is paid for columns and other stones of large dimensions, but many such stones sell for 90 cents per cubic foot, and the increasing number of our public and monumental buildings, creates an extensive demand for such large masses.

I trust that we shall never again have occasion to see a public edifice, which ought to be a model of fine architecture, constructed of brick, and I doubt not, that the improving taste of our citizens will soon require more elegant materials for their dwellings than baked clay. Indeed, the effect of a blood-red brick city, is decidedly disagreeable to any person of taste, and is the first annoyance to which such persons are exposed on approaching our shores.

The rapidity with which a granite building may be constructed, is decidedly in favor of stone edifices, and I have no doubt that the materials may be furnished at nearly as low a price.

In this section I shall describe only those quarries which, from their situation, are available for commercial use.

If

I should undertake to describe minutely every locality in the State, where good granite is found, this report would be swelled into a large volume, for I have more than thirty dif

ferent kinds before me, suitable for architecture, that were obtained in Maine, during the past summer, and there are many other localities, which not being available for commercial use, it was not thought worth while to represent.

The following quarries are all capable of being successfully wrought, and are situated near the sea-coast from whence they may be sent abroad.

On the Penobscot river there occur inexhaustible supplies of excellent granite rocks, admirably suited for architectural purposes, and so near navigable water as to render the stone valuuable for exportation.

At the base of Mosquito mountain, beside a huge pile of rocks that have fallen from the mountain's side, and exposed a steep precipice of naked rock, the Frankfort Granite company have begun extensive operations for obtaining building stones. Thus far they have wrought only those detached blocks, that lie in confused heaps at the base of the mountain, by which much expense is saved in quarrying. Extensive buildings or sheds are erected to cover the workmen and their materials, and while engaged in dressing the stone.

This quarry was first wrought in the month of May, 1836; since that time more than $50,000 worth of granite has been sold. It has been mostly sent to New York, and is there used in constructing the Albany Exchange. That contract not yet being completed, the Frankfort Granite Company have not felt so severely as other quarrying associations the decline of business which has arrested so many other enterprises of the kind. There can be no doubt, if this quarry is properly managed, that it will become an immense and increasing source of revenue, both to the individuals immediately interested and to the State. A considerable sum, no less than $20,000, has been expended in digging a large sloop canal from the river to the base of the mountain, and that work must have consumed a considerable share of the proceeds from their sales, but when the work is complete, it will so favor the shipments as to make ample returns to the company. I am in hopes to obtain some statistical information respecting the operations at this quarry, and

shall then be able to give a more accurate account of its value.. The whole mass of Mosquito mountain is composed entirely of granite, and its height is 527 feet above high water mark, while the diameter of the mountain is at least twice the measure of its height, and it must contain at least five hundred millions of cubic feet, equal to 30,000,000 tons.

Mount Heagan appears to be composed of similar rocks.

Mt. Waldo is composed of the same kind of granite and is elevated 968 feet above high water mark. This mountain contains more than one billion five hundred millions cubic feet of granite, or one hundred millions of tons.

This stone is of excellent quality, is free from stains of oxide of iron, and does not contain any pyrites. It is an admirable stone for architecture, and will preserve its color unchanged. Its effect, when seen at a little distance, is much like that of the light colored granite of Hallowell. When examined minutely, the crystals of felspar become apparent, since, like the Mosquito mountain granite, it contains squares of felspar or is porphyritic in its structure.

Preparations were making for opening an extensive quarry upon the side of Mt. Waldo, at the time when we visited it, and I doubt not that the work will prove advantageous to the parties concerned. A road has been made so as to transport the stone directly to the river, where it can be put on board ship and sent to the cities where it is wanted.

I have seen specimens of the Mosquito Mountain granite finely dressed and polished. It is like that above described, and is vastly more beautiful than any of the oriental granites used by the ancient Romans.

Many other quarries have been opened in Frankfort, but few of them are wrought for the purpose of shipping abroad. I have described them so minutely in our topographical section that it will be unnecessary to recapitulate.

BLUEHILL.

Bluehill bay is a very convenient harbor for vessels engaged in transportation of granite, and there are immense and inex

haustible quarries of this stone favorably situated for transportation. The New York Granite Company have opened extensive quarries about 1 mile E. S. E. from the village, on the North East side of the narrows, and very near navigable water. The rock is coarse-grained, but when hammered, looks very handsome. Owing to the presence of black mica, it is a little darker than those before described. Columns weighing 35 tons have been split from this ledge, and others may be obtained which will weigh 84 tons. The mountain is elevated about 300 feet above the sea, and is about half a mile in extent E. S. E. and W. N. W. No less than six hundred millions of cubic feet of stone are contained in this hill within the limits of half a mile in length, by 1000 feet in width, and 300 feet in height.

The company own 250 acres of this mountain, and paid for it the sum of $5500. A railroad 70 rods in length costing $10 per rod has been made for the purpose of bringing the stone from the top of the hill, but it is entirely unnecessary, since it will be easier to quarry upon its side near the water, to which there is a regular and easy slope. Railroads so highly inclined as this, are very apt to get out of order, owing to the heavy loads carried upon them, and the wear and tear is so great that continual expenditures to a large amount are required to repair them.

This quarry, if well managed, must prove of great value, for the quantity of stone is inexhaustible, and transportation to mar

ket easy.

The Mc-Herd ledge at the head of Long's cove, has not been opened, but the stone seen there is a very fine kind of granite, splitting into any form desired and presenting a sharp and well defined edge. It is suitable for ornamental work and the most elegant devices may be carved upon it, which will present delicate sculpture to great advantage. I should recommend this stone for the capitals of columns and for window-caps which ornamental work should be carved. I do not know the extent of this granite, as much of it is evidently covered with soil, but there is amply sufficient for the purposes above designated.