UP to the present time, there has been but one book on the subject of Chimneys printed in the United States, that of Armstrong's, revised by F. E. Idell, and published in the Van Nostrand Science Series. It is a treatment of chimney-draft only. Other than this, the only book of any pretension is that of Bancroft's, an English book, published in 1885, and no longer obtainable. Thus it may be seen that there is no book which contains the latest practice in regard to the theory and designing of chimneys as built in the United States.