October, 19 lo 



AMERICAN HOMES AND GARDENS 



Xlll 



SEWAGE AND ITS DISPOSAL. A 



review of modern methods. 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 

 by 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 loio -Supplement Catalogue 

 FREE to any address 



MUNN & COMPANY 

 361 Broadway New York 



DENATURED ALCOHOL FROM CACTI 



BY P. E. m'cLENAHAN. 



IF the great Southwest is ever reclaimed 

 and made to produce vegetation that 

 will be profitable, it must be done by 

 developing the native plants instead of at- 

 tempting to introduce new species and try- 

 ing to acclimate them. With this idea in 

 view, the United States Department of 

 Agriculture has been directing the experi- 

 ment stations and encouraging work upon 

 the cacti. 



For more than six years the experiment 

 station at Las Cruces, New Mexico, has 

 been experimenting with the prickly pear 

 and other cacti. This species has been 

 planted, and it was found that by throwing 

 it upon the ground 85 per cent, of the 

 pieces grew, while only 91 per cent, of the 

 parts planted in a furrow grew. The rows 

 were planted ten feet apart, and then left 

 without cultivation, irrigation, or attention 

 for three, four and five years. By this time 

 the rows had spread until they were from 

 six to eight feet wide, and only left a small 

 path between them. 



Then began a large series of experiments. 

 The fruit of the cactus (tunas) was 

 gathered. It is almost as large as an egg, 

 of a dark red color, and filled with seeds. 

 The coloring matter was first extracted, 

 and found to make an excellent fruit color- 

 ing for jellies and confectionery. Then the 

 sugars were examined and six kinds were 

 found, and after long, tedious processes, 

 each sugar was fermented and in time 

 turned into alcohol. Then came careful 

 weighing and mathematical calculations to 

 determine the amount of denatured alcohol 

 that could be produced from an acre, and 

 the minimum of cost. 



Final deductions gave most satisfactory 

 results, and it was proven that $150 worth 

 of denatured alcohol could be produced per 

 acre after an average growth of four years 

 for the plants. At this rate a quarter sec- 

 tion of now arid land could be made to 

 yield a gross income of $24,000, and this 

 would be almost a perpetual yield, as the 

 fruit is borne annually, and the plants need 

 no replanting, cultivation, or irrigation, and 

 grow upon the poorest soil in the arid re- 

 gions. 



BOATS OF REINFORCED CONCRETE 



BOATS were first constructed of rein- 

 forced concrete by Gabellini in Rome. 

 They have been described in these 

 columns. Concrete boats are now made in 

 Germany. In April, 1910, a scow intended 

 for use in dredging and similar work was 

 launched in Pomerania. The boat is 33 

 feet long and 13 feet wide, and has a capa- 

 city of 22.5 tons. It consists of four water- 

 tight compartments. The end compart- 

 ments are decked and serve only as air 

 chambers, while the middle compartments 

 are open at the top and can be used for the 

 reception of cargo. The total depth of the 

 boat is about 4^ feet; its weight is 17 tons, 

 and its draft when unloaded is 20 inches. 

 It is constructed like an iron or wooden 

 vessel, of transverse frarnes, longitudinal 

 beams, and plates. The plates are about 3 

 inches thick. The frames and beams are 5 

 xlO inches. The bulwark is stiffened be- 

 tween the frames by a plate 8 inches high 

 and iy2 inches thick, to which are attached 

 oaken buffers extending entirely around the 

 vessel. According to the Engineering 

 News, scows made of reinforced concrete 

 are also to be used in the dredging opera- 

 tions of the Panama canal. One of these 

 scows is already launched. It weighs, com- 

 plete, 27 tons and has a draft of 4 feet. 



The Cigaret 

 you can 

 smoke all 

 day without 

 a trace of 

 "nervas"— 

 because it's just 

 pure, clean, sweet 

 tobaccos, blended by 

 artists. Prove it. 



MAKAROFF 

 RUSSIAN 

 CIGARETS 



15 cents and a quarter 

 AT YOUR DEALERS 



Mail address — 95 Milk Street, Boston 



BURCHARTZ American 



Long-Span Floor Systems 



Specially Adaptable to Fireproof Residence Construction. 



^ Combination Concrete and Terra Cotta Floors reinforced in 

 two directions. Absolutely Fireproof, Soundproof, Vermiproof. 

 Endorsed bv municipalities and builders as the Last Word in 



Economy, Safety and Simplicity of Construction. 



^ Use any standard form of reinforcing material and can be laid 

 from our specifications by any competent mason builder. 



A Saving of 15 to 25 Per Cent. Over Otlier Systems 



^ These floors can be laid in single slabs up to 40x40 feet without 

 supporting girders or columns, with flat, unbroken, all terra cotta 

 or concrete ceilings upon which plaster can be applied d'rect)> 

 without the use of lath. The ideal floor construction for schools, 

 sanitarium'', private residences, garages and all types of commer- 

 cial buildings and factories. Investigate before you build. 

 Handsome Book Free. 



BUILDING IMPROV[M[NT COMPANY 



1-7 Madison Avenue, New York City 



AMERICAN 

 HOMES a^id 

 GARDENS 



- and = 



SCIENTIFIC 

 AMERICAN 



will be sent to 

 one address for 



$5.00 



Regular Price ... S6. 00 



