Scientific American Supplement, No. 601, July 9, 1887 eBook

This eBook from the Gutenberg Project consists of approximately 127 pages of information about Scientific American Supplement, No. 601, July 9, 1887.

Scientific American Supplement, No. 601, July 9, 1887 eBook

This eBook from the Gutenberg Project consists of approximately 127 pages of information about Scientific American Supplement, No. 601, July 9, 1887.

French cross bond, otherwise diagonal bond (liaison en croix), is English bond, but with the peculiarity that in every fourth course one header is made use of in the stretcher course at the quoin.  The result is that the stretchers break joint with each other, and all the joints range themselves in diagonal lines, and if in any part of the work headers of a different brick are introduced, the appearance of a cross is at once brought out; and even without this the diagonal arrangement of joints is very perceptible and pleasing.

Besides wall building, the bricklayer has many other works to perform.  He has to form fireplaces, flues, chimneys, and the flat trimmer arches which support the hearth, and has to set the stove, kitchen range, copper, etc., in a proper manner.  He has to form various ornamental features and much else, some of which we shall have an opportunity of noticing rather later.  The strangest business, however, which is intrusted to the bricklayer is building downward—­by the method known as underpinning—­so that if a foundation has failed, a sounder one at a greater depth may be reached; or if a basement is required under an existing building which has none, the space may be excavated and the new walls built so as to maintain the old.

This work has to be done with great caution, and bit by bit, and is usually left to experienced hands.  The mode in which the mortar joints of a brick wall are finished where they show on the external or internal face is a matter worth a moment’s attention.  It is important that the joints of the work shall be so finished as to keep out wet and to be as durable as possible, and it is desirable that they should improve, or at any rate not disfigure, the appearance of the work.

The method which architects strongly advocate is that the joints shall be struck as the work proceeds—­that is, that very shortly after a brick is laid, and while the mortar is yet soft, the bricklayer shall draw his trowel, or a tool made for the purpose, across it, to give it a smooth and a sloping surface.  This is best when the joint is what is called a weather joint—­i.e., one in which the joint slopes outward.  Sloping it inward is not good, as it lets in wet; finishing it with a hollow on the face is often practiced, and is not bad.  Bricklayers, however, most of them prefer that the mortar joints should be raked out and pointed—­that is to say, an inch or an inch and a half of the mortar next the outer face be scratched out and replaced with fresh mortar, and finished to a line.

In cases where the brickwork is exposed to frost, this proceeding cannot be avoided, because the frost damages the external mortar of the joints.  But the bricklayers prefer it at all seasons of the year, partly because brickwork is more quickly done if joints are not struck at the time; partly because they can, if they like, wash the whole surface of the work with ocher, or other color, to improve the tint; and partly

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Scientific American Supplement, No. 601, July 9, 1887 from Project Gutenberg. Public domain.