BULLETIN No.JT^ ^MAY, I890. 



METEOROLOGICAL OBSERVATORY 



(.)!■■ IlIK 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



Latitiide, 42° 23' 48.5" N. Longitude, 72° 31' 10" VV. 



Height of instruments above ground, 51 ft. Above sea level, 260 ft. 



inONTHLY SUMMARY. 



I'ressiire. lii iiu'lies. Actual maximum reading 30.033 ; actual inininunu reading- 29.'23o; 

 Mean reduced to sea level, 29.959; Monthly Range, .80. 



*.4ir Tc III i>i- VII t lire. In Degrees Fahrenheit. Highest, 77'^; 80"; Lowest, 37.5"; 31.5"; 

 Mean, 57"' ; 5(i.:>' ; Monthly Range, 4S.,5'', 39.5" ; H ighest I\Ieau Daily, 64.9°, eti.S" ; Lowest Wean 

 Dailv, 4S.9'\ 48..5'; Mean" Maximum, 6t).9'', H8.8'^; Mean Minimum, 47.1'^, 43.8''; Mean Daily 

 • Range, 19.9°, 24.9"; Greatest Daily Range, 31.5"; 36.5°. 



Humitliti/, Mean Dew Point, 58°; Mean Force of Vapor, .5.335; Mean Relative 

 Humidity, 67.1. 



tViiid. Prevailing Directions, N. 15 per cent., S. 19 per cent., 'S.S.W. 23 per cent.» 

 N.W. 8 per cent., other directions 35 per cent.; Total Movement, 5284 miles; Greatest 

 Daily Movement, 330 m. 20th ; Least Daily Movement, 84 m. 24th; Mean Daily Movement, 

 170 miles; Mean Hourly Velocity, 7.1 miles; INLaximum Pressure per Squai-e Foot, 16 1-2 

 lbs.=58 m. per hour, 20th, at 10-30 a. i\i. 



Precipitation. In inches. Total Precipitation, 4.56 in. ; at base of tower 5.39 in. 



Wcathrv. Mean Cloudiness observed, .59 per cent; Number of Clear Days, 10; Number 

 of Cloudy Uays, 12; Number of Fair Days, 9; Total Cloudiness recorded by the Sun 

 Thermonieter, 235 hrs, or 51 per cent. Number of days on which .01 inches or more rain 

 fell, 14. 



Kriglit Sunshine. Number of Hours Recorded, 225. 

 . Mean Ozone, 39 per cent., aurora 15th. 



Frost, 12th. Lunar Corona, 31st. Thunder and Tyightning, 14th and 28th. 



DAILY SUMMARY, 



May 1. Barometer reduced to sea level, max. 29.985, miii. 29.72, mean 29.80. 



♦Temperature, max. 72*, 75", 12 m., min. 45.5", 45.5'^, 12 p. m, mean hourly 56.6" 



Sun Thermometer, max. 119°, 10-30 a.m., briiiiit sunshine fi hrs. 



Mean deAV point 48.7*, mean force vapor .503G, mean humidity 74. 



Wind, N., total movement, 193 m., mean hourly velocity 8 m., max. pres- 

 sure, 7 3-4 lbs. =39 m. per hour, 11 a.m. Ilaiu began falling at about~4 p. 

 M., and ceased at about 7 p.m. .06 inch water fell ; at base of tower, .09 in. 

 Ozone 40. 



2. Barometer reduced to sea level, max. 30.21, min. 29.985, mean 30.1(13. 

 Temperature, max. 62", 64°, 4p.m., min. 37.5*, 33°, 5 a.m., mean hourly 48.9'^ 

 Sun Tliermometer, max. 119°, 1-30p.m., bright sunshine 13 3-4 hrs. 



Mean dew point 39.3°, mean force vapor .4117, mean humidity 62. 

 Wind, N.E., total movement 149m., mean liourly vel. 6.2 m., max. pressure 

 7 1-4 lbs.= 38 m. per hour, 1-30 a.m. Ozone 60. 



3. Barometer reduced to sea level, max. 30.19, min. 29.995, mean 30.09. 

 Temperature, max. 66*, 68°, 4 p.m., min. 42°, 38.5*. 2A.:\i.,mean hourly 53.9*. 

 Sun Thermonieter, max. 106*, 2 p.m., l)right sunshine 10 hrs. 



Mean dew point 46.3°, mean force vapor .4557, mean humidity 72. 



Wind, S. S.W., total movement 267 ni., mean hourly vel. 11.1 m., max. pressure 



7 1-4 lbs.= 38 in. per hour, 12 m. A trace of rain fell in the latter part of 



the evening. Ozone 40. 



*The first flgui-es denote reacUngs at top of tower, the second at base. 



