FORESTRY. 745 



have proved most resistant to cold arc indicated and attention is called to 

 (he most improved nietliods of cultivation to secure both production of fruit 

 and resistance to cold. 



The experiments to date have shown that the only varieties which are 

 sufficiently frost resistant to be used in commercial plantings are the Kum- 

 quat and the Satsuma. By selecting favorable sites, planting windbreaks, 

 giving good cultivation, and sowing winter cover crops, the danger from 

 frost injury can be greatly reduced. It is recommended, however, that no 

 extensive planting be made without some well-defined plan for fighting the 

 frost. 



Experiments in the use of orchard heaters during the winters of 1911 and 

 1912 are described. The author concludes in substance that although there 

 is no question as to the value of orchard heaters as an aid in frost pro- 

 tection, since the freezes that occurred in the winters of 1911 and 1912 would 

 tax to the utmost anj^ system of oi'chard protection, it is yet to be deter- 

 mined whether orchard heaters may be used for a number of years under 

 Texas conditions with a degree of profit to the grower. Shortly before cold 

 weather is expected all varieties of citrus fruits should have clean earth 

 piled above them to a height of 12 to 18 In. In case of a severe freeze all 

 wood thus covered will be saved. 



The better oranges, limes, and lemons, E. Chavez (Estac. Agr. Cent. 

 {Mexico] Bol. 67, 1012, pp. 12, pis. .'i2). — This comprises descriptive accounts 

 of the principal species and varieties of citrus. 



FORESTRY. 



The Michigan woodlot, J. F. Baker (Michigan Sta. Cire. 17, pp. 107-122, 

 figs. 6). — This is a brief popular treatise on woodlot management. It discusses 

 llie scojie of farm forestry, the present condition of Michigan woodlots, timber 

 estimating, woodlot protection, cutting, reproduction, establishment of new 

 -tt^oods, and species and soils. A short note is also given relative to the State 

 cooperative woodlot work. 



Forty years' management of woods, D. Tait {Quart. Jour. Forestry, 6 

 (1912). No. Jf, pp. 279-29S). — This comprises a report of the management of the 

 woods on the Owston Park estate, near Doncaster, England, for a 40-year period 

 with special reference to the financial returns secured. 



The relative yields obtained by the destructive distillation of different 

 forms and species of hardwoods, L. F. Hawley and R. 0. Palmer (Orig. 

 Commun. 8. Internat. Cong. Appl. Chem. [Washington and New York], 6 {1912), 

 Sect. IV, pp. 138-146). — Tests made to determine the commercial value of dif- 

 ferent species of hardwoods as raw material for distillation are described. 

 Data obtained in each of the distillations, together with the average yields of 

 alcohol and acid from different parts of the tree, are given for beech, birch, 

 maple, gum, chestnut, and hickory. 



Distillation of resinous wood by saturated steam, L. F. Hawley and R. C. 

 Palmer {Orig. Commun. 8. Internat. Cong. Appl. Chem. [Washnigton and New 

 York]. 13 {1912), Sect. Via, pp. 151-176, figs. 5). — This is a report of an inves- 

 tigation of the fundamentals of the steam distillation process. Pitchy longleaf 

 pine was used in the distillation tests. The results are presented in tabular 

 form and discussed. Consideration is given to the effects of the size of chip, 

 pressure of steam, speed of distillation, and end point at which distillation is 

 stoppetl, on the yield of total oil, the composition of the oil, and the amount of 

 steam required to remove the oil. 



