130 THIRTEENTH AXXUAL REPORT 



downy mildew. What has been said above in regard to the dis- 

 ease in the cucumber is equally applicable to the muskmelon. 



Ap2^le Tree Canker. — A disease known as apple tree canker has 

 during the past two or three years been attracting the attention of 

 students of plant diseases. We desire to get an idea of its preva- 

 lence in New Hampshire. To that end we urge apple growers to 

 note its presence or absence in their orchards. 



The canker usually presents the following characters : It at- 

 tacks limbs of one to three or more inches in diameter ; the dis- 

 eased part may be from a few inches to two or more feet in extent, 

 is usually more or less swollen, its surface is covered with rough- 

 ened or cracked bark darker in color than normal. The disease is 

 believed to be caused by a fungus. We have at present no remedy 

 to recommend. 



H. H. Lamson, 



Bacteriologist. 



DEPARTMENT OF METEOROLOGY 



Observations for the year July 1, 1900, to July 1, 1901, have 

 been continued as usual and have been under the immediate 

 charge of E. P. Jewett, New Hamj)shire College, class of 1901, 

 as observer. 



Signal flags, indicative of the weather for the succeeding night 

 and day, have been displayed from the tower of the Experiment 

 Station building, from 11 a. m. until sunset eacli day except Sun- 

 days and holidays throughout the year. 



The humidity of the atmosphere has been determined, through 

 the growing season only, by readings of the wet-bulb ther- 

 mometer. 



The summary gives interesting comparisons of temperature, 

 precipitation, cloudiness, and prevailing wind direction, together 

 with averages covering the past six years. The mean temperature 

 for the year, as determined from the average of 8 a. m. and 8 p. m. 

 observations, was 46.5 degrees Fahrenheit or six tenths of a degree 

 higher than the average for six years. The mean as obtained 

 from the maximum and minimum readings was 46.6 or seven 



