444 EXPEEIMENT STATION RECORD. 



varieties lose their vitality in a greater degree than do the blacli-seeded va- 

 rieties of the same year's crop. Nearly all varieties from the 1904 crop gave 

 as good results as were obtained in general from the 1909 crop. 



FORESTRY. 



Tree guide, Julia E. Rogers {Garden City, N. Y., 1914, PP- Till +265, figs. 

 244). — A popular guide to the trees common to the eastern half of Canada and 

 the United States. In addition to the native species the most important cul- 

 tivated species brought from other countries are also described. 



Yellow pine, A. T. North (St. Louis, Mo., 1913, 4. ed., pp. 130, figs. 22; rev. 

 in Engin. News, 11 {1914), No. 12, p. 649, 650).— This handbook contains tables 

 of the strength of beams, grouping the timbers in terms of their depth ; factors 

 for converting safe loads to other fiber stresses than that on which the tables 

 are based ; deflection ; properties of actual size Instead of nominal size timbers ; 

 maximum bending moment; strength of wooden columns; trussed beams; joists, 

 trusses, and nailed and spiked joints; and tests of timbers. 



On the conditions for the natural occurrence of spruce, P. E. Mijlleb 

 {Ceutbl. GesaiH. Forstic, 40 {1914), No. 1-2. pp. 11-27). — A review of European 

 literature dealing with the factors influencing the natural distribution of spruce 

 trees. 



Influence of precocity of thinning on the yield of regular stands of spruce, 

 E. Mee {Rev. Eaux ct Forets, 53 {1914), Nos. 11, pp. 345-349; 12, pp. 377-386).— 

 As a result of observations conducted over a period of 30 years and here 

 reported, the author concludes that early thinning undertaken with a view of 

 favoring the development of future trees have accelerated the diameter and 

 volume growth of the trees, and have likewise increased the financial returns. 



Can the yield of rubber from Hevea trees be increased by commercial fer- 

 tilizers? A. W. K. DE Jong {Teysmannia, 25 {1914), A'O. 3, pp. 139-144, pi. 1).— 

 In the experiments here reix»rted potassium, phosphoric acid, and sulphate of 

 ammonia were tried, both alone and in combination, as fertilizers for the 

 Hevea rubber tree. The increased yield of rubber secured by the use of com- 

 mercial fertilizers, particularly a complete fertilizer, appears to warrant a 

 further thorough investigation of the subject. 



[The rubber industry in Brazil] {Min. Agr. Indus, e Com. [Rio de 

 Janiero] Monograph, 1913, Nos. 9, pp. 4^+32, pis. 19; 10, pp. 26, pis. 10; 11, 

 pp. 78, pis. 5; 12, pp. 51; 13, pp. 32, figs. 9; 14, pp. Ill +118+55, pis. 50, figs. 

 14; 15, pp. 49, pis. 16; 18, pp. 30, pis. 22; 19, pp. 31+22, pis. 20; 20, pp. 22+12, 

 pis, 4), — This comprises a series of monographs containing descriptive and 

 statistical accounts of the rubber industry in various regions of Brazil. The 

 monographs given in order corresponding to the numbers above listed are as 

 follows: The Rubber Industry in Pernambuco, by N. C. Pereira de Andrade: in 

 Alagoas, by L. de Moraes; in Sergipe, by A. M. Rabello; in Bahia, by A. Her- 

 menegildo da Silva ; in Espirito Santo, by A. A. Campos da Cunha ; in Rio de 

 Janeiro, by A. Pereira da Silva; in Sao Paulo, by G. Catramby; in Januaria, 

 State of Minas Geraes, by C. Guimaraes junior; in Goyaz, by J. Guedes de 

 Amorim ; and balata rubber, by G. Barroso. 



Note on a latex hydrometer, B. J. Eaton {Agr. Bui. Fed. Malay States, 2 

 {1914), No. 9, pp. 224-226). — The author briefly describes a hydrometer which 

 has proved satisfactory for tropical use in determining the rubber content of 

 latex. 



[The lumber industry in Wisconsin], Mary Dopp {Bui. Amer. Geogr. Soc, 

 45 {1913), No. 10. pp. 736-749. figs. 4). — A brief historical and statistical review 

 of lnn)l)ering and foi-estry in Wisconsin. 



