BULLETIN No 21. SEPTEMBER, 1890 



METEOROLOGICAL OBSERVATORY 



OK TIIK 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



Latitude, 4'2° 23' 48.5" N. Longitude, 72° 31' 10" W. 



Height of instruments above grotmcl, 51 ft. Above sea levels 260 ft. 



MONTHLY SUMMARY. 



I're.tsiire, In inches. Actual maxiimun reading 30.13; actual minimum reading 29.45; 

 Mean reduced Xo f^ea level, 30.124; Monthly Range, .68 in. 



*Aif Tetnperttture, In Degrees Fahrenheit. Highest, 79-°; 80.5"; Lowest, 32"; 28.5"; 

 Mean, SK.T'^; 60.4^^; Monthly Hangc, 47'', .32''; Highest Mean Daily, 70.2'^, 72.5*^; Lowest Mean 

 Daily, 46.2'-'', 45>' ; Mean Maximum, 67.8^', 71.8°; Mean Minimum, 5 •G'^, 49.1'-''; INIean Daily 

 Range, IG.L', 22.7'=; Greatest Daily Range, 34°; 43.5'-\ Least Daily Range, 4"; iO°. 



Hutnhliti/. Mean Dew Point, 55.8-'; Mean Force of Vapor, ..5800; Mean Relative 

 Humidity, 80.9. 



IVind. Prevailing Directions, N. 23 per cent., S. 20 per cent., N.N. E. 11 per cent., 

 S.W. 10 i)er cent., other directions 36 per cent.; Total Movement, 3.507 miles; Greatest 

 Daily Movement, 281 m., 13th: Least Daily Movement, 32 m. loth and 30th; Mean Daily 

 Movement 116.9 miles; Mean Hourly Velocity, 4.9milps; Maximum Pressure per Square 

 Foot, 5 lbs.=32 m. per hour, 13th, at 11-30 A. m". and 24th at 11 A. M. 



PrecipltHtion. In inches. Total Precipitation, 4.86 in. ; at base of tower 5.85 in. 



Weather. Mean Cloudiness observed, 5S. 7 percent; Number of Clear Days, 11; Number 

 of Clou<ly Days, 13; Number of Fair Days, 6; Total Cloudiness recorded by the Sun 

 Thermometer! 221 1-2 hrs., or 58 per cent. Number of days on which .01 inches or more rain 

 fell, 13. 



Bright Sunshine. Number of Hours Recorded, 166. 



Mean Ozone, 47 per cent. 



Lunar corona, 2.5tli, 30th. 



Thunder and TAghtnituj , 5th, 13th, 17tli. 



Frost, 2.5th. First of the season. 



DAILY SUMMARY, 



Sept. 1 Bavoiiieter reduced to sea level, max. 30.26.5, rain 30.0!), mean 30.217. 



♦Temperature, max. 70.5'^, 79.5°, 1 p.M.,min 51. 5°, 45", 4 a. ;m., mean hourly 61.6° 



Sun Thermometer, uiax. 139^, 11 a.m., bright sunshine 11 1-2 hrs. 



Mean dew point 53.3°, mean force vapor .6091, mean humidity 69.7. 



Wind, W., total movement, 73 m., mean hourly velocity 3 m., max. pres- 

 sure. 1-2 lb. =10 in. per hour, 4-30 P.M. Ozone 40. 



2 Bai-ometer i-educed to sea level, max. 30.295, min. 30.18, mean 30.232. 

 Temperature, max. 78°, 79°, 5 p.m., min. 47.5°, 42°, 5 am, mean hourly 64.3°. 

 Sun Tliermometer. max. 131°, 10 a.m., In-ight sunshine 13 1-4 hrs. 



Mean dew point 54^, mean force va|)or .6704. mean humidity 68. 

 Wind. W., total movement 69 m., mean hourly vel. 2.9 ni., max. pressure 

 I 1-2 lbs.= 17 ra. per hour, 2-30 p.m. Ozone 40. 



3 Barometer reduced to sea level, max. 30.25, min. 30.195, mean 30.228. 

 Temperature, max. 75.5°, 79°, 5 p.m., min. 51°, 41. 5°, 6 a.m., mean hourly 63.5°. 

 Sun Thermometer, max. 130°, 11 a.m., bright sunshine 5 hrs. 



Mean dew point 59.7°, mean force vapor .6792, mean humidity 79. 

 Wind, N., total movement 45 m., mean hourly vel. 1.9 m. 



4. Barometer reduced to sea level, max. 30.255, min. 30.16, mean 30.207. 

 Temperature, max. 74°, 75.5°, 5 p.m., min. 56°, 52.5°, 6 a.m., mean hourly 64.6° 



*The first figures denote readings at top of tower, the second at base. 



