WEATHER IN CRANBERRY CULTURE 



39 



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H A M P £ N 



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Scale - Miles 



Map 2. Outline Map of Massachusetts showing: 



(1) Shaded parts where cranberries are cultivated. 



(2) Small numbered circles, the locations of the observing stations providing data for 



the forecasting formulas. 



(3) Small black circles, the locations of other cranberry weather observing stations. 



The construction of the various formulas seems to reveal the following, in the 

 relations they cover: 



1. They are all straight-line relations.^^ 



2. The relations change steadily with the advance and retreat of summer and 

 much faster in the spring than in the fall. 



3. The wet-bulb temperature methods of Angstrom^" and Keyser.^i though 

 properly rejected by Ellison^^ in the forms in which they were advanced, were 

 evidently real approaches to fundamentals. As modified and applied here,^^ 

 they are useful in computing minimum bog temperatures. The writer has failed 

 to find a way to use the Young formula^^ with comparable results, but it may 

 deserve further stud^'. 



4. The dew point is significant in the evening but not at noon. 



5. The lowest of the dew points at the various stations is important in the 

 evening in the spring and late summer. Wherever it is, it tends to command the 

 situation before morning. As it usually is at Milton, Paxton, or Worcester, and 



^^The addition of considerable amounts to the observed data before using a divisor in some of 

 the formulas gives the line a more gradual slant. 



^^Angstroem, I. .Anders, Studies of the frost problem, Geografiska Annaler, January 1920, pp. 

 20-32. Abstracted by J. Warren Smith in U. S. Monthly Weather Rev. 48:640-641, 1920 (copy 

 in the Middleboro library). 



^^Keyser, Elgie M., Damaging temperatures and their calculation in advance by simple arith- 

 metic. Proc. Wash. State Hort. Assoc, for 1922, Olympia, Wash., pp. 97-103. 



"Ellison, Eckley S., A critique on the construction and use of minimum-temperature formulas, 

 U. S. Monthly Weather Rev. 56:485-495, 1928. 



**The wet-bulb temperature is most widely useful employed directly, but is helpful indirectly in 

 the evening formulas that use the dry-bulb temperature with the dew point. 



^*U. S. Monthly Weather Rev., Supplement No. 16. 1920, pp. 53-58; Ellison, op. cit., pp. 493-495; 

 Allen, Charles C, Minimum temperature forecasting in the central California citrus district, U. S. 

 Monthly Weather Rev. 67:286-293, 1939. (Copy in the Middleboro library.) 



In varied form this formula is used in frost forecasting in the West more widely than any other. 

 It is based on the dew point and relative humidity. 



