BULLETIN No. 20. AUGUST, I 890. 



METEOROLOGICAL OBSERVATORY 



Ol' Til 10 



Hatch Experiiiieiit Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



LiUitiule, 12° 23' 4S.5" N. Longitude, 72° 31' 10" W. 



Height of instruments above ground, 51 ft. Above sea level, 200 ft. 



MONTHLY SLiMMARY. 



I're.iniire, In inches. Actual maximum rc.ailing .'50.00; actual miiiiiuum reading '29. IS; 

 Mean rciluceil to sea level, 30.001; Monthly Range, .82 in. 



*Aiy Ti'iii/K-riiture. In Degrees Fahrenheit. Highest, 86.5°; 88.-'>"; Lowest, 47'^; 41.5"; 

 Mean, (>7 .-2"'; 1)7.2-'; Monthly Range, 39.5«, 47'''; Highest Mean Daily, 7 7", 78"; Lowest Mean 

 Daily, 54. 0'-', 56.5'^ ; Mean Maximum, 75*^, 78.'2"; Mean Minimum, 5!).3", .50.2'^; Mean Daily 

 Range, 15.7, '22'-'; Greatest Daily Range, '23*^; 30.5". Least Daily Range, G"; 15.5". 



Hiiuiulitii. Jlean Dew Point, .57.2"; Mean Force of Vapor, .83'2G; Mean Relative 

 Humidity, 71 i). 



Vind. Prevailing Directions, S. 16 per cent., N. 14 per cent., S.W. 14 per cent., 

 S.S.W. 10 per cent., other directions 46 per cent.; Total Movement, 4116 miles; Greatest 

 Daily Movement, 250 ni., 5th; Least Daily Movement, 52 m. Sth ; Mean Daily Movement, 

 132.8 miles; Mean Hourly Velocity, 5.5m"iles; Maximum Pressure per Square Foot, 13 

 11)S.=51 ni. per hour, 19th, at 9-30 P. M. 



ft'ecipitation. In inches. Total Precipitation, 4.06 in. ; at base of tower 4.88 in. 



Ifi'fftlirr. Mean Cloudiness observed, 57.1 percent; Number of Clear Days, 8; Number 

 of Cloudy Days, 15; Number of Fair Daj's, 8; Total Cloudiness recorded by tlie Sun 

 Thermometer, "230 lirs., or .53.6 per cent. Number of davs on whicli .0] inches or more rain 

 fell, 14. 



Uriyht Snn.thine. Number of Hours Recorded, 199. 



Mean Ozone, .58.7 per cent. 



Itnlos, Lunar corona, '28th. 



Thunder and l^ightning, 1st, 5th, 14th, 17th, 19th. 



Aurora, 14th, ISth. Gales 17th and 20th. 



DAILY SLfMiVlARY. 



Au<!; 1. Barometer reduced to sealevel, max. 30.095, miii. 29.845, mean 29.997 

 ♦Temperature, max. 85.5''', 86", 4 p.m., min. (19", 68", 12 p.i\i, mean liourly 75°. 

 Sun Tliermometer, max. 135", 12-30 p.m., l)ri,iiiit sunsliine 4 lirs. 

 Mean dew point 68.7", mean force vapf)r .9249, mean luimidity 77.3. 

 Wind, S.E., total movement, 111 m., mean hourly vel<^city 4.6 m., max. |ires- 



sure, 1 1-5 lbs. = 15 m. per hour, 11-30 a.m. Rain Ix-gan fallinu- alxuit 2 a. 



M. and ceased al)out 7 A. M. .10 in. water fell; at l)ase of tower. 12 in. 



Ozone 60. 



2. Barometer reduced to sea level, max. 30.205, min. 30.095, mean 30.167. 

 Temperature, max. 86. 5", 87. 5°, 3 p.m., min. 66*^,63.5", 2 a.m., mean lionrly 75.]^. 

 Sun Tliermometer, max. 140", 10-30 a.m., l)ri,iilit sunsliine 14 lirs. 



Mean dew point 67.3", mean force vapor .9911, mean linmidity 69. 

 Wind, S., total movement 102 m., uu^au liourly vel. 4.3 m., max. pressure 

 2 Ibs.= 20 m. per hour, 4 p.m. Ozone 50. 



3. Barometer reduced to sea level, max. 30.235, min. ;!0. 12, mean 30. 1 7. 

 Temperature, max. 82", 84", 3 p.m., min. 62. 5", 60. 5", 5 a.m., mean liourly 72.4". 

 Sun Thermometer, max. 130", 10-30 A.i'vi., l)ri<>iit sunshine 12 hrs. 



Mean dew jioint 06.3°, mean force vapor .9168, mean humidity 72.7. 

 Wind, S.S.W. , total movement 138m., mean hourly vel. 5.S ui.,ma\. pressure 

 2 1-2 lbs. =22 m. per hour, 7-30 p.m. Ozone 50. 



*Tlie first figures ilenote readings at top of tower, the second at base. 



