252 EESULTS OF COMPARATIVE OBSERVATIONS: PRUSSIA. 



Bavaria, at two places at each station, the open fields and under wood- 

 laud shade, and twice daily, at 8 a. m. and at 2 p. m. They iuclude 

 records upon the temperature of the air at 1.5 meters above the earth 

 and at the heifiht of the tree-tops, humidity, evaporation, rain and snow- 

 fall, temperature of the soil at the surface and at the depths of 0.15, 0,3, 0.6, 

 0.9, and 1.2 meters ; also, barometer, direction and force of winds, kind 

 and amount of clouds, and general characteristics of the day. They also 

 include notices of all meteorological phenomena observed, and records" 

 of first appearance of flowers, leaves, «S:c., and other events in animal 

 and vegetable life that depend upon the seasons. The arrangement of 

 instruments and mode of taking observations are entirely similar to those 

 in Bavaria, as already described, with the exception of those relating to 

 loose materials upon the ground in the woods, and the temperature 

 ■witiiin the body of the trees, which are omitted, while observations are 

 added for obtaining the temperature and moisture of the air at the level 

 of the tree-tops. 



These observations are too recent to afford important results, and but 

 one of the stations the first year gives results through the entire period. 

 The thermometers are of the centigrade scale, and metrical measures are 

 adopted throughout These observations are under the direction of Dr. 

 A. Miittrich, professor of experimental physics and meteorology in the 

 Koyal Forest Academy at Neustadt-Eberswalde. 



SOME EESULTS OF ONE YEAR'S OBSERVATION (1875) AT THREE PRUSSIAN FOREST 



STATIONS. 



[The stations in the follo-sving tables are designated by numbers, as follows : 



1. J^nVdncft«rode, latitnde. 51° 22'; longitude, 28° 14' east ; elevation, 353 meters. 



2. Holierath. latitude, 50° 27 J' ; longitude, 24° 3J' east; elevation, 612 meters. 



3. CarUherg, latitude, 50° 2a' ; longitude, 34° 2' east; elevation, 690 meters. 



The timber at station 1 was beech, 65 to 85 years old ; and at 2 and 3 pines, 45 years old ] 



Temperatures. (Centigrade.) 



By comparing the above observations it will be seen that the difference 

 between fields and woodlands was more considerable in the growing 

 months, and for the general average of the year, the woods were cooler 

 than the fields, except in the winter, when the woods were warmer than 

 the open fields. 



The temperature at the tree-tops was in most cases above that of the 

 air below, and the difference was much greater in summer than in winter. 

 It is to be further noticed that the range of difference was considerably 

 most with respect to the beech woods, and from June to September, the 

 greatest difference appeariug in August. 



