This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
It will generally be found necessary that the ceilings and walls which are not covered with paper or hangings, shall be tinted or frescoed. This is a matter which needs to be done by care ful workmen who understand the preparation and application of the colors. Much depends upon the first or sizing coat and this should always be applied before tinting or fresco of any kind is done.
It is usually the custom to send the sashes to the building all glazed, so that the superintendent needs only to see that the glass is of the specified quality and whole. Common window glass is called sheet or cylinder glass, and is rated as double or single thick, and as first, second or third quality. Formerly all glass was imported from France or Germany, but American glass has come to be used in general in the greater part of the United States.
In the Eastern States window glass is still imported and it is customary in the East to specify German glass for the best work. For lights up to twenty-four inches in width, single-thick glass may be used, this is about one-sixteenth of an inch in thickness, while double-thick glass is about one-eighth inch.
The best quality of common American glass is known as AA, the second as A, and the third as B. Sheet glass is made by blowing the molten glass in a cylinder about fifteen inches in diameter. This is trimmed and cut longitudinally and heated until it can be opened out flat. Sheet glass always retains a vestige of its curvature.
Between first and second quality glass it will be difficult to distinguish except by practice, but defects or unevenness may be seen at once, and plate glass is always readily distinguished, by reason of its polish and its absolute freedom from imperfections of any kind.