METEOROLOGICAL DATA, DOUGLAS LAKE MICHIGAN, 1912-1918. 



BY FRANK 0. GATES AND KUTH K. MURD. 



In order to place the meteorological data of the Douglas Lake region where 

 it can be more available, the following tables were prepared by Ruth E. Hurd 

 and F. C. Gates for presentation at the 1919 meeting of the Michigan Academy 

 of Science and for publication in its annual report : 



Location : Douglas Lake is located in Cheboygan County, Michigan, in the 

 extreme upper part of the Lower Peninsula, about equidistant from Charle- 

 voix, Mackinac City and Cheboygan. The Biological Station of the University 

 of Michigan is located along the Southeastern shore of Douglas Lake. 



Instrumentation: Weather instruments were maintained in the imme- 

 diate vicinity of the Log Laboratory just back from the shore of Douglas Lake. 

 Readings of each instrument were taken twice daily, during the summer 

 session, at 7 A. M. and 7 P. M., Eastern Time, and recorded on forms which 

 are filed in the station archives. 



Tempcfaturc: The temperature readings were obtained from a Sixe 

 Thermometer exposed under the open aquarium shed. The readings give the 

 (lay and night maximum and minimum temperatures. With a few exceptions 

 the same readings also give the 24-hour, midnight to midnight, maxima and 

 minima. In these exceptions the midnight reading was obtained directly 

 when it was evident that such a reading would be necessary, or calculated 

 from a late night and an early morning reading by assuming a iniiform rise 

 or fall in temperature between such readings. Su(;h would be the case not 

 more than three or four times during the summer. The tables here following 

 are expressed on the basis of midnigbl to midnight temperatures. Should the 

 work of an investigator necessitate the separation of tlic night i)eriod from 

 the day period, he is referred to the records on lile at the Biological Station 

 and in duplicate at Ann Arbor, Michigan. 



Precipitation: Rainfall records were obtained l)y the use of a funnel 

 rain gauge and expressed in Inches and hundredths. 



Pressure: Barometric readings were recorded at the station and are on 

 lile but are not included in this report. 



Evaimralion: Since 1915, records -of evaporation have been obtained in 

 connection witli atomometer studies on various features of the vegetation, but 

 have not been worked up for inclusion in this reix>rt. 



21 et Mich. Acad. Sci. Kept., 1919. 



