September, 1910 



AMERICAN HOMES AND GARDENS 



XV 



SEWAGE AND ITS DISPOSAL. A 



review of modern inethods. By H. 

 Lemmoin-Cannon. Scientific American 

 Supplement 1551. 

 ELECTRIC LIGHTING FOR AMA- 

 TEURS. How a small and simple ex- 

 perimental installation can be set up 

 at home. Scientific American Supple- 

 ment 1551. 

 CHEMICAL AFFINITY. Simply ex- 

 plained by Sir Oliver Lodge. Scienti- 

 fic American Supplement 1547. 

 CASE-HARDENING. By David 

 Flather. Scientific American Supple- 

 ment 1547. 

 ELECTRIC IGNITION SYSTEMS. A 

 comprehensive article by E. W. Rob- 

 erts. Scientific American Supplement 

 1546. 

 CONCRETE. A general article on its 

 merits and defects. Scientific Ameri- 

 can Supplement 1543. 

 REINFORCED CONCRETE. Some of 

 its Principles and Applications with 

 practical Illustrations. Scientific 

 American Supplements 1547, 1548, 

 1551. 

 ELECTRONS AND THE ELECTRO- 

 NIC THEORY are discussed by Sir 

 Oliver Lodge in Scientific American 

 Supplements 1428, 1429, 1430, 1431, 

 1432, 1433, 1434. 

 WIRELESS TELEGRAPHY. Its Pro- 

 gress and Present Condition are well 

 , discussed in Scientific American Sup- 

 plements 1425, 1426, 1427, 1386, 1388, 

 1389, 1383, 1381, 1327, 1328, 1329, 1431. 

 HOW TO CONSTRUCT AN EFFI- 

 CIENT WIRELESS TELEGRAPH 

 APPARATUS AT SMALL COST is 

 told in Scientific American Supplement 

 1363. 

 SELENIUM AND ITS REMARK- 

 ABLE PROPERTIES are fully de- 

 scribed in Scientific American Supple- 

 ment 1430. The paper is illustrated by 

 numerous engravings. 

 LANGLEY'S AERODROME. Fully de- 

 scribed and illustrated in Scientific 

 American Supplements 1404, 1405 and 

 1546. 

 STEAM TURBINES. Their Construc- 

 tion, Operation and Commercial Ap- 

 plication. Scientific American Supple- 

 ments 1306, 1307, 1308, 1422, 1400, 1447, 

 1370, 1372, 1521. The articles have all 

 been prepared by experts in steam en- 

 gineering. 

 PORTLAND CEMENT MAKING is 

 described in excellent articles con- 

 tained in Scientific American Supple- 

 ments 1433, 1465, 1466, 1510, 1511. 

 THE TANTALUM LAMP. A full illus- 

 trated description of a lamp having a 

 metallic filament and burning at once 

 without preliminary heating appears in 

 Scientific American Supplement 1523. 

 THE WATERPROOFING OF 

 FABRICS is thoroughly discussed in 

 Scientific American Supplement 1522 

 bv an expert. 

 THE SPARK COIL, ITS CONSTRUC- 

 TION AND MAINTENANCE, is the 

 subject of a painstaking article in 

 Scientific American Supplement 1522. 

 ELECTRIC IGNITERS FOR GAS EN- 

 GINES are discussed in Scientific 

 American Supplement 1514. 

 CARBURETERS, a subject of immense 

 importance to automobilists and the 

 users of oil engines, is well treated in 

 Scientific American Supplement 1508. 

 EPICYCLIC TRAINS, which play an 

 important part in toothed gearing, are 

 ably described in Scientific American 

 Supplement 1524. 



Each number of the Scientific American 

 Supplement costs 10 cents by mail 

 Send for iqto Supplement Catalogue 

 FREE to any address 



MUNN & COMPANY 

 361 Broadway New York 



MORTAR 



LIKE all other compounds, mortar de- 

 pends for its quality upon that of its 

 constituents, and also upon the pro- 

 portions in which they are used, and the 

 method by which they are mixed. To all 

 intents and purposes, it is an exceedingly 

 fine concrete, composed of an aggregate 

 and a matrix mixed with water, its pur- 

 pose being to fill up the interstices in the 

 joints between the bricks or stones of which 

 a wall is composed, so as to provide an 

 even bedding surface, and render the wall 

 water-tight, its adherent properties being 

 rather more valuable for securing this, than 

 needed to prevent the bricks from being- 

 pulled apart. 



Thus it comes about that the more close 

 is the jointing of a wall, the finer should be 

 the grain of the mortar, and of its aggre- 

 gate. A coarse rubble wall having wide 

 irregular mortar joints would be best with 

 a mortar made of a fine gravel or crushed 

 stone, or, at least, with one which contained 

 a considerable amount of pea-sized lumps 

 as well as finer sand among the aggregate, 

 to assist in filling up the larger hollows 

 without undue liability to settlement. On 

 the other hand, for well-dressed ashlar 

 masonary, the finest sharp-grained sand 

 obtainable should be used, there being only 

 very small cavities to fill up, and the very 

 thinnest possible joint being required. 



Beyond this, it is necessary in all cases 

 that the aggregate should, under a magni- 

 fying glass, display either sharp edges or a 

 roughened surface or both, in order that the 

 matrix may adhere to it ; for, while there 

 is little necessity to stick the bricks of a 

 wall together, if they be properly laid, it is 

 cjuite necessary that the mortar should form 

 in itself a homogenous substance, else it will 

 crumble into dust or wash out of the joints. 

 Chippings of a soft stone crushed in a mor- 

 tar will form an excellent aggregate, when 

 obtainable, especially if sifted to various 

 grades of fineness for dififerent work ; and 

 old bricks similarly crushed are even better, 

 as being rougher in texture. Sharp pit- 

 sand is, perhaps, most commonly specified, 

 but it should be really sharp, and no, as is 

 frequently the case, rounded by attrition — 

 in reality, from the bed of an old river, 

 though now dug from a pit. In the same 

 way it should be free from salt, and pit- 

 sand from a prehistoric sea beach is some- 

 times as salt as that gathered on the ex- 

 isting shore, for salt attracts moisture, and 

 a wall built with salt sand in the mortar will 

 scarcely ever dry. 



For the same reason sea water must not 

 be used for mixing; but this objection 

 against the use of sea sand and sea water 

 disappears in the case of many boundary 

 and retaining walls, which need not become 

 dry, though the result of their use is fre- 

 quently an unsightly fungus-like efflor- 

 escence on the face of the wall. 



So far as the matrix is concerned, an or- 

 dinary mildly hydraulic ground stone lime is 

 in almost universal use for ordinary build- 

 ing. Pure or poor limes are alike unsuit- 

 able, having no setting property, but merely 

 drying, and being consequently easily 

 washed away by rain ; and, although some 

 prefer to reduce their lime to powder by 

 slaking, it is much better to buy it ready- 

 lime day by day as it is required, the usual 

 proportion being about three measures of 

 sand to each measure of lime. 



Many architects specify two and a half 



IN EVERY ROOM 



of your house, you should have a mantel. 

 It combines furniture with architectural finish; 

 beauty with utility. With or without a 

 fireplace a 



Wood Mantel 



is a good investment, adding many limes its 

 cost to the value of the house — a point every 

 home builder should consider. Here is a 

 refined and beautiful design, particularly 

 adapted for a dining room. Many others, 

 as well as practical suggestions for the home 

 builder are shown in our booklet 



Why Wood Mantels? 



Send free, if you address 



Wood Mantel Manufacturers' 

 Association 



H. T. BENNETT, Secretary 



Room 1218, State Life Building, Indianapolis, Ind. 



JUST PUBLISHED 



THIRD EDITION OF 



KIDDER'S 



Cijurcfjes! »■"> Cijapels 



By F. E. KIDDER, Architect 



This edition has been thoroughly revised by 

 the author, and enlarged, many new designs 

 being added, including several new designs for 

 Catholic churches. There are 120 illustrations in 

 the text and more than 50 full-page plates. 

 The book contains a large number of plans and 

 perspectives of churches of varying costs. Be- 

 sides this there is much concise and practical in- 

 formation relating to planning and seating ; 

 details of Construction, Heating and Ventilation, 

 Acoustics, etc., making it in its present form 



T/ie Best American Book on 

 Church Design and Construction 



One oblong quarto volume. Price, net, $3.00 

 MuNN & Co., Inc., 361 Broadway, N.Y. City, 



