LOCATION AND EQUIPMENT. 



The meteorological observatory is located in the tower at the 

 southeast corner of South College at an elevation of about 50 feet 

 above the ground. It was equipped with a number of Draper self- 

 recording instruments and the records date from Jan. i, 1889. The 

 location is on a gravel ridge with an open exposure to the north, 

 west and southwest, with slightly higher ground about a mile to the 

 south and a ridge considerably higher about half a mile to the east. 



The top of the tower is 72 feet above ground, and the exposure is 

 good in all directions. The anemometer, anemoscope, wind pres- 

 sure instrument and electrical sunshine recorder are mounted from 

 3 to 5 feet above the top of the tower and the recording apparatus is 

 in the room below. The thermometer shelter and rain gauges are 

 on the campus about 300 feet southwest from the tower and on 

 slightly lower ground. 



The observatory is in latitude 42° 23' 48.5" N., longitude 72° 31' 

 10" W., and the base of the tower is 223 feet above mean low water, 

 Boston harbor, as determined by levels connecting with those of the 

 Boston and Maine railroad. The standard barometer is of U. S. 

 Weather Bureau pattern, reading to i-5ooth of an inch, and the 

 cistern is 2733^ feet above sea level. The Draper self-recording 

 barometer is mounted one foot higher. 



The sunshine recorder of the Draper pattern was replaced by an 

 electrical one from Friez in igo6, and the Draper anemometer by 

 one of U. S. Weather Bureau pattern, at about the same time. The 

 records are received on a triple register, which also records the 

 rainfall. The rain gauges are about two feet above ground and 

 218 feet above sea level. A U. S. Weather Bureau gauge is used in 

 determining the precipitation, and the tipping bucket electrical 

 recording gauge in determining the time and rate. 



The Draper self-registering thermometer. Weather Bureau pattern, 

 maximum and minimum thermometers and hygrometer are in a stan- 

 dard shelter about four feet above ground and 220 feet above sea 

 level. 



On Jan. i, 1904, the time of making observations was changed 

 from 7 A. M., 2 p. M. and 9 p. m., to 8 a. m. and 8 p. m., so as to 

 conform with the practice of the U. S. Weather Bureau. This 

 change should be noted in comparing the dew point and relative 

 humidity before and after that date. Other data are probably not 

 affected by the change. 

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