If the sand and stone are both dark colored, the building will have a lurid aspect; for the proportion of lime in the mortar (one-eighth or one-ninth) is too small to whiten it sufficiently, but if the sand is a light gray, the contrast of the colors with dark stone, will be pleasing.
Cobblestones of any size not exceeding six inches in diameter may be used, but for the regular courses on the outside those of two inches in diameter should be preferred. Small stones give the building a much neater aspect. Two inch stones are very neat, though three inch stones will answer. The inside rows of stones may be twice as large as those on the outside.
The mortar is composed of one bushel of fresh stone lime to eight or nine bushels of clean sharp sand. As the strength of the building depends on the goodness of the mortar, it is very important that sand of the first quality should be obtained. Yellow sand or any sand that contains clay should be rejected. Gray sand is sometimes found so pure as not to discolor the water into which it is thrown, and such should be procured if possible.
Mortar that has been made some weeks is generally preferred. Some masons are particular to reduce the lime to a thin paste, and then while it is hot to apply the sand. The thickness of the wall is sixteen inches, though twelve inches will answer very well for the gable ends above the garret floor.
When the foundation, or cellar wall is leveled and prepared, a layer of two (or two and a half) inch of mortar is spread over it, and the stones are pressed into the mortar in two rows which mark the outside and inside of the wall, leaving about an inch between each adjoining stone in the same row. If the wall is to be grouted, the two rows are formed into two ridges by filling the vacancy between the stones with mortar, and the space between these two ridges (about a foot in width) is filled with such stones as are not wanted for the regular courses. The grout is then applied. If the wall is not to be grouted however, the mortar should be carefully pressed round every stone, making the wall solid without flaw or interstice*. When one course is leveled, begin another.
Between every two adjoining courses on the outside some have the mortar to project as far out as the stone, in a regular line round the building. It is wrought to an edge with the trowel, and adds to the neatness as well as to the strength of the wall; for during the process the mortar is pressed round each stone; and the smoother it is made, the stronger it will be, and the better will it resist disintegration.
It has generally been the practice to have the corners formed of cut stone; but in a two story building [Ven-1 Vanorman] erected last season within a few miles of us, this expense was avoided by rounding the corners and using cobblestones. The stone is not the only saving by this plan; however, much of the masons time is consumed in laying such corner stone.
On the first mentioned building, the workman were employed by day. Four walls, amounting to 146 feet in length, were commonly raised eighteen inches every day by three masons. This is a little short of 99 cubic feet of wall or six perches* to each workman. Sometimes in damp weather they had to stop a while for mortar to set.
The building erected last season was constructed for by the perch at 37-1/2 cents, and half of this sum additional, was allowed for the tender. The walls, however, were grouted - that is, all the interstices between the stones were filled with liquid mortar; and this substance must have more time to set. For this reason no more than three courses a day can be laid in dry weather; and not any when it is showery.
It requires from ten to twelve bushels of sand to a perch besides the lime when made into mortar; and cobblestones lie in a heap when thrown from the wagon about as compactly as they do in a wall.
If cobblestone buildings are as cheap as wood, as one of those proprietors believe, they will be much cheaper in the long run; and this will be evident when we consider the frequent paintings which are necessary to keep a frame house in decent repair.
P. S. Since writing the above, I have received two communications from persons who have had cobblestone houses erected. One says, "The thickness of the wall is measured from the outside of the stones. Pieces of timber, 4 x 6 inches and two feet long, are used for setting the lines. These lines are laid in the courses just finished, and the line is drawn through saw-cuts just 16 inches apart."
The other says, "the cost of cobble is about 1/6 th less than brick; and probably 1/4 or 1/3 less than wood, - on the supposition that the stone may be laid within a mile, and sand within two and one-half miles." It must be evident, however, that the expense of cobble, brick, wood and stone, must differ considerably in different places, according to the prices of those materials and the distance they have to be carried. - "Alb. Cultivator* D. T. Greatfield Cayuga County."
* Glossary