May 1, 1913.] 



THE INDIA RUBBER WORLD 



435 



The Editor's Book Table. 



THE RUBHKR TREE BOOK. BY W. F. DE BOIS MACI.AREN. 

 London, 1912. M.iclaren & Sons, Limited. [Cloth, 308 pages, with 

 83 illustrations: price, lis. 6d. post free.] 



WHILE it may be considered by some that everything pos- 

 sible has been said about rubber, the rapid and continuous 

 growth of the industry involves so many new considera- 

 tions, that there is always room for a well considered and com- 

 prehensive work, such as that recently produced by Mr. Maclaren. 

 His intimate connection with rubber, as director of various suc- 

 cessful planting and financial companies, gives him special facili- 

 ties for treating his subject. Having had a period of large and 

 constantly increasing yields, with the result of big dividends, 

 rubber companies have not up to now experienced the need of 

 special efficiency in estate working. It is, however, being more 

 and more recognized, that efficiency is no less essential to success 

 in the rubber-growing industry, than in any other. 



It has been the author's purpose to arouse the interest of the 

 planter in the soil he cultivates and the trees he grows there, by 

 showing how varied and wonderful are the phenomena connected 

 therewith. In the words of the introduction, the object with 

 which the book has been written has been to assist in obtaining 

 better results than in the past, on more economical lines, and 

 with a view to the future welfare of the rubber-growing industry. 



Starting with the general consideration of "What a Tree Is," 

 Mr. Mac-laren takes up the question of the soil and its fertility, 

 manuring, weeding and other subjects; leading up to the seed and 

 its reproduction through roots, stem and foilage. At this point 

 he quits the botanical division of the subject for that of cultiva- 

 tion, dealing successively with "Land Grants" ; "Elevation" ; 

 "Roads, Bridges and Dams," "Felling and Burning," as well as 

 various other points. 



Next in order come the questions more directly affecting 

 planting ; including nurseries, planting-out and pruning. 



Of special interest to estate owners, is the chapter on "Planting 

 Distances." Mr. Maclaren arrives at the conclusion that a dis- 

 tance of 30 X 30 feet, or 48 trees to the acre, is not too wide. While 

 it would involve at first a little sacrifice, later results would more 

 than pay for waiting. An instance is recorded from Sumatra, in 

 which three isolated trees eleven years old yielded in 1912 over 

 100 pounds each of rubber. Mr. Maclaren remarks that 48 such 

 trees per acre would, on this basis, produce annually 4,800 pounds, 

 while 400 pounds per acre is considered a very good yield from 

 closely planted trees. 



Proceeding to the subject of extraction, the questions of tapping 

 and coagulation are next dealt with, both in principle and prac- 

 tice. Under the former head the various methods of incision are 

 treated on the basis of trials made at experimental points, while 

 the merits of different tapping knives and utensils are likewise 

 discussed. In the treatment of the question, "The Latex and 

 How It Is Coagulated," latex is considered as a reserve of plant 

 food, representing only about 2 per cent, of the total volume of 

 nutriment, and being intermingled with other elements of no 

 service as food reserves. Mr. Maclaren disputes the correctness 

 of Dr. Stevens' suggestion that the resins in trees must be stores 

 of plant food also if latex is. The functions of late.x are con- 

 sidered under various aspects, it being added that the co-opera- 

 tion of natuve has a wider scope than many dream of. 



When the coagulation of the latex has brought it out of the 

 hands of nature into an industrial form, it becomes available for 

 mechanical treatment. Under this head washing mills are con- 

 sidered from various points ; including the width and speed of 

 rollers and loss in weight. The process of creping is finally dealt 

 with. This naturally leads up to the subject of the grading of 

 rubber; the opinion being expressed that (instead of five as had 

 been suggested) three grades should be quite sufficient for all 



purposes, namely, first late.x rubber; second grade earth 

 rubber. Drying, smoking and packing occupy the following 

 chapters. 



Most direct interest attaches to Mr. Maclaren's estimate of the 

 cost of production, for arriving at which he thinks there should 

 be a standard way. When any estate is producing 100,000 pounds 

 of dry rubber a year, he considers the cost f. o. b. should not 

 exceed Is. 6d. (36 cents) per pound. He adds that such a figure 

 ought to be looked upon as having to be reduced each successive 

 year, till it is well under l.y. (24 cents) per pound. 



Every page of this work contains some statement of interest ; 

 the whole volume reflecting high credit upon its author. 



K.\LENDER FUR DIE GUMMMNDUSTRIE. EDITED BY DR. KURT 

 Gottlob. Berlin, 1912. Union Deutsche \'erlagsgesellschaft. l8vo, 

 514 pages, cloth.] 



The last annual issue of the Gummi-Kalender (to call it by 

 its abbreviated title) is fully up to the mark of its prede- 

 cessors. Its main divisions include a diary with blanks for 

 memoranda of prices and names of manufacturers of supplies; 

 details of the various organizations connected with the German 

 and Austrian rubber industries ; rubber washing and manufac- 

 turing tables. In its miscellaneous section there is a discus- 

 sion of the risks of poisoning in the rubber industry. 



In the supplement, the "Annual for the Rubber Industry," is 

 a chronological calendar of the history of rubber from 1536 to 

 the present time; followed by an article on the "Chemistry of 

 Rubber," from the pen of the editor. Next in order come 

 articles on "The Technology of Rubber," "Analysis of Rubber 

 and Rubber Goods," "Practical Testing of the Qualities of Rub- 

 ber Goods," "The Coloring of Rubber Goods," and "Viscosity 

 of Rubber Solutions." The value of this work is materially en- 

 hanced by various groups of statistical tables. 



Any one in a position to follow the intelligent arrangement of 

 the Calendar and its supplement will find them of material value 

 as a guide in technical operations and as a compendium of facts 

 affecting the rubber industry. 



GUIMMI-ADRESSBUCH, 1913. (RUBBER DIRECTORY, 1913.) UNION 

 Deutsche Verlagsgesselschaft. Berlin. [8vo, cloth, 578 pages.] 



The 11th edition of this directory of the German rubber in- 

 dustry has lately appeared in its accustomed form, displaying a 

 steady increase in the number of names. As it will be recalled 

 by those familiar with the work, the cities of Germany are 

 classified in alphabetical order; in each case the separate sections 

 of the trade showing the names of the local houses in the dif- 

 ferent branches. The names in each city are thus concentrated, 

 the handy little volume being therefore specially adapted for use 

 by those personally visiting the centers of the German rubber 

 industry. 



A separate section is devoted to Austria-Hungary, filling 16 

 pages, arranged in the geographical order of the cities and 

 towns referred to. A number of advertisements are interleaved 

 or appear in the body of the text. Any one wishing to arrive 

 at the details of the German manufacture and distribution of 

 rubber and asbestos goods will appreciate this directory for its 

 completeness. 



RUBBER STOPPERS IN CHAIR LEGS. 



A man out in California with an inventive turn of mind writes 

 to "Popular Mechanics" that he has discovered a very inexpen- 

 sive way of preventing chairs from marring the floors. He gets 

 four rubber stoppers and then bores a hole the size of the stopper 

 in the lower end of each chair leg, and inserts the stopper so that 

 it projects slightly below the wood. This is something that 

 anybody with an auger the proper size can do for himself. 



