454 EXPERIMENT STATION RKCOUD. 



th(^ \iirifitions in temperatiiro of troos in wliich the temperature of oak 

 and pino trees of ditierent diameters were compared with the temper- 

 ature of the open tiekl. The author reports a variation of al)out 4 F. 

 between the temperature of the open Held at a distance of 10 rods 

 from the temperature readings of a nari-ow strip of woodland where 

 these experiments were conducted. The readings of the ditferent 

 thermometers for the month of February are given and comparisons 

 made with temperatures taken from apple trees in another series of 

 investigations. The records show that the temperature of trees of the 

 smaller diameter follow more nearly that of the atmosphere than in 

 the case of the larger trees. The temperature of the trees did not 

 respond to slight variations in the external temperatures and never 

 reached the same maxima and minima as shown by the thermometers 

 in the open air. Decided variations in the temperature of the open 

 air were followed by similar variations in the internal temperature of 

 the trees in from 24 to 72 hours, depending largely upon the diameter 

 of the trees. 



The second part of the paper reports a summary of results of obser- 

 vations to determine the amount of growth made b}^ a series of trees 

 during the growing season of 1898. The moisture content of the same 

 trees was determined at the same time. The trees investigated were 

 the American elm, black walnut, Carolina poplar, magnolia, red oak, 

 sugar maple, and white ash. All these trees were 10 3'ears old, with 

 the exception of the Carolina poplar, which was 6 years old. In height 

 the trees varied from 15 to 25 ft., and in diameter from 3 to 5 in. 

 Measurements were made of the upright, terminal, and lateral branches, 

 and are recorded in tabular form. The percentage of moisture in the 

 same trees was determined, in which it is shown, as would naturally 

 be expected, that the softer woods contained the highest percentage of 

 moistui'c. 



The production of high-class oak, ash, and larch timber, W. 

 ScHLicH {G'frd. Oht'on., 3. xer., 27 {1900). Xo. 697. pp. 27 J^, 275).— 

 Suggestions are given for the proper management of these species for 

 the production of timber in England. All are light demanding, are 

 thin crowned, and none of them improve the yield capacity of the 

 locality if raised in pure woods. The best way of rearing them is 

 said to be to mix them with the shade-producing, full-crowned species. 

 The species best adapted for this purpose is said to be beech. 



Oak and beech mixtures and ash and ])eech mixtures are described 

 at some length. The growing of larch and beech is of particular 

 importance since the larch disease has spread throughout Great Brit- 

 ain. Oak, ash, and larch woods may be under planted with silver firs 

 instead of beech. Scotch pine has been used with favorable results in 

 the same wav. 



