DEPARTMENT REPORTS. 127 



REPORT OF THE MICHIGAN WEATHER SERVICE. 



FOR THE FISCAL YEAR ENDING JUNE 30, 1911. 



The operation of the Weather Service has been confined to the gen- 

 eral lines of endeavor that have prevailed for some years past and of 

 these, the collection, compilation and filing of detailed records from 

 voluntary observers is the principal one. 



The service was inaugurated to cooperate with the United States 

 Weather Bureau and secure in detail a thorough knowledge of Michigan 

 climatic conditions and it is very admirably accomplishing this result. 

 There are ten regular "Weather Bureau Stations in the state. All but 

 two of them, Grand Rapids and Lansing, are lake shore observatories. 

 There were at the close of the fiscal year, one hundred and thirteen 

 cooperative, or voluntary observation stations from which reports were 

 received monthly. All of these stations keep a record daily of the 

 highest and lowest temperature, amount of precipitation, if any, gen- 

 eral or prevailing direction of the wind and general character of the 

 day as regards cloudiness. The observers also note the actual depth of 

 the snow on the ground from day to day, if there is any, and under 

 miscellaneous phenomena, keep a record of the occurrence of frost and 

 lother irregular meteorological data. The voluntary observers as a 

 general rule, have been and are now doing splendid work and their re- 

 ports are very reliable, regular and prompt. 



The value of the observations, which are taken entirely by public 

 spirited or interested citizens without any pay whatever, is of untold 

 importance to the state at large. The records find a wider and more 

 extensive use from year to year and are a very important factor in de- 

 veloping, the agriculture of the state. 



As agriculture has developed, the influence of climate in all its 

 phases has become a recognized factor. The records of the Michigan 

 Weather Service supply detailed and valuable information on this sub- 

 ject for nearly every general locality and for every section of the state. 

 For instance, we have just been able to draw graphic charts showing the 

 average occurrence of the last killing frost in spring and the first kill- 

 ing frost in autumn ; the time between these dates shows the average 

 length of the crop growing season. Additional charts have also been 

 published showing the occurrence of the last known killing frost in 

 spring and the earliest known killing frost in autumn. Reference to 

 these charts develops the fact that all of the Lower Peninsula of Mich- 

 igan has a much longer crop growing season than other states in the 

 same latitude. 



Besides their use for scientific purposes, the records are entering into 

 many other fields of development of the state's resources. In locating 

 water plants a long record of rainfall in connection with the stream 

 flow, is of insistent and decided value. The records are constantly being 

 used in a large variety of law casas to settle disputed points regarding 

 weather conditions, and they furnish valuable information to the medi- 

 cal fraternity and the civic engineer. 



