METEOROLOGICAL OBSERVATORY 



OF THE 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE 



Latitude, 42° 23' 48.5" N. Longitude 72' 31' 10" W. 



Height of barometer above ground, 51 ft. Above sea level, 2yj.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No 208. 



APRIL, 1906. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maximum reduced to freezing, 30.14. 3d, q A. 

 Minimum reducedto freezing, ag.io, 25th, 12 m. 

 Keducedf maximum reading, 30.45, 3d, 9 A 

 Kediicedf minimum reading, 29.40, ajtli, 12 M 



Mean semi-daily reduced. 29.9S1 



Monthly range i.oj 



*Air Temperature. In Degrees Fahr. 



Highest, 74-5. 'Ot'ii 3 >'•• 20th, 4 P. 



Lowest 21.0, 3d, 6 a. 



Mean liourly, 45-' 



Mean of means of max. and min 45.9 



-Mean sensible (wet bulb), 40.2 



Monthly range, 53-5 



Highest mean daily 55.8,19th 



Lowest mean daily, 32.9, 2d 



Mean maximum, 58.3 



Mean minimum, 33.6 



Mean daily range, 24.7 



Greatest daily range, 42.0, 29th 



Least daily range, ....... 9.5, i3th,23d 



Humidity. 



Mean dew point 34.7 



Mean force of vapor, 301 



Mean relative humidity, 70.3 



Precipitation. In inches. 



Total precipitation, 3.25 



Number of days on which .01 inch or more 



rain or melted snow fell, 10 



Total snow in inches, 2 



• Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 4777 ni. 



Greatest daily movement, .... 436 m., 24th 



Least daily movement, 36 m., 19th 



.Mean daily movement, 159111. 



Mean hourly velocity, 6.6 ni. 



Maximum pressure per square foot, lo.o lhs.= 



45 m. per hour, 24th, i p., N.N.W. 

 Maximum velocity for 5 minutes, 36 ni. per 



hour 24th, 2 P., N.N.W. 



Prevailing Direction, North. 



Summary. 



North, Northeast, 33 percent. 



North, 20 " " 



South, 10 " " 



Southwest, 10 " " 



Other directions, 27 " " 



Weather. . 



Mean cloudiness observed, . . . .49 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, i33hrs.=34 per cent. 



Number of clear days, 13 



Number of fair days, 13 



Number of cloudy days, 4 



Rright Sunshine. 



Number of hours recorded, . . 269 hrs.=66# 

 Rnin, 4th, 5th. 6th, Sth, 9th, loth, 14th, 15th, 



2oth, 23d, 30th. 

 Go/**, 35 miles or more per hour, 45 m. 24th, 



N.N.W.; 35m.2Sth, N. 

 Snow, Sth, gth, 23d. 

 Thunder and Iiightning, 30th. 



