_Good Housekeeping Institute Engineering._ Good Housekeeping. _Vacuum Cleaning Systems._ M. S. Cooly, Heating and Ventilation Magazine. _Chemistry._ Herman Vulté. _Chemistry and Physics._ May B. Arsdale, Dr. Woodhull. _Bureau of Building Bulletin_ 1922, N. Y. C. Municipal Building. U. S. Government Bulletins on all home problems, see the list of the U. S. bulletins on all home processes. _Building, Plumbing, Fire, etc._ Bulletin Bureau of Board of Standards and Appeals, City of N. Y., Dec. 23, 1919. _Bulletin Bureau of Board of Standards and Appeals City of N. Y._ Building, Plumbing, Fire etc., Dec. 23, 1919. _More Leisure Hours._ Louise Read--Society for Electric Development Pamphlet, 522 Fifth Ave. _U. S. Government Pamphlets._ Bureau of Printing, Washington D. C. (Sup. of Documents). _Electrical Record._ (_Magazine_) McGraw Hill Co. Inc. _Electrical Merchandising._ (_Magazine_) Gage Pub. Co., Inc. _Laundry Pamphlets._ Wallace B. Harts. Transcriber’s Notes The language used in the source document, including unusual, archaic, inconsistent and erroneous spelling, hyphenation and capitalisation, has been retained, except as mentioned below. The same applies to grammatical errors, missing words and punctuation, confusing or contradictory texts, the inappropriate use of units, etc. Neither spacing inconsistencies (for example between numbers and their units) nor textual inconsistencies (for example in prices or in the use of principal vs. principle) have been standardised. Page xxii, ... safe and sure insect ostracizer: the caption under the illustration is ... safe and sane insect ostracizer. Page 6, cost calculation: as printed in the source document, despite obvious errors and inconsistencies. Paragraph starting “It is necessary when ordering a range ...: the closing quote mark is lacking. Pages 100 and 104, see Plan 1: this was not present in the source document. Page 131, ... mixture of 21 parts nitrogen, 79 parts of oxygen ...: the proportions should be reversed, and should be read as parts per 100 for nitrogen and oxygen, not per 10,000. Page 221, flavoring cream with or without condensed milk.: there may be a comma missing between flavoring and cream. Page 221, ... (granites frozen by oscillation and frappés ...: the closing bracket is lacking from the source document. Page 262, paragraph starting You are particularly interested ...: one or more words may be missing. Changes made: Illustrations have been moved out of text paragraphs. The (single) footnote has been moved to directly underneath the paragraph to which it refers. Some obvious minor typographical and punctuation errors have been corrected silently. Several tables have been split or re-arranged slightly for better readability; in some tables ditto marks have been replaced with the dittoed text.