104 ELEVENTH ANNUAL REPORT 



these omnipresent little plants. The milkman desires to sup- 

 press them entirely; the butter and cheese maker seeks to 

 encourage the development of some species and to suppress 

 that of others. In the manure pile myriads of bacteria are 

 working, according- to circumstances, rendering the contained 

 plant-food more available on the one hand, or causing its loss 

 on the other. In the soil they are working' with the same vari- 

 able result. Certain bacteria or bacteria-like plants grow on 

 the roots of peas, clover, vetches, and related plants (the 

 legumes), producing little nodules or tubercles; in some way 

 they seem to enable the legumes to make use of a portion of 

 the vast supply of nitrogen contained in the atmosphere, from 

 which tise most plants seem to be barred. As a more extended 

 knowledge of the bacteria is acquired, it is more than possible 

 that we shall be able to control their activity where hereto- 

 fore it has been left to chance with variable result. 



H. H. LamsO'N, 



Bacteriologist. 



DEPARTMENT OF METEOKOLOGY AND AGRICIL- 



TURAL ENGINEERING 



I. Meteoeolooy 



Observations have been continued as during previous years 

 with Charles T. Staniels, I^ew Hampshire College, class of 

 1901, acting as observer during most of the year. 



Signal flags have been displayed each day, except Sundays 

 and holidaj^s, throughout the year from the tower of the experi- 

 ment station building, indicative of the weather for the suc- 

 ceeding night and day. In addition a synopsis of weather 

 conditions has been written each day upon the blackboard at 

 the station building for the benefit of the station workers. 



A Draper self-recording thermometer has been added to the 

 equipment, and it has proved very useful in checking the 

 maximum and minimum daily readings, as well as in other 

 ways. A wet bulb thermometer to indicate the humidity of 

 the air has also been procured, and its readings taken during 

 the growing season from April to Xovember. 



