Frosts in New York 519 



and where every additional day that the crop stands increases its feed 

 value, and with machinery in general use by which a large acreage may be 

 cut in a few hours, warnings of frost might be used to great advantage. 



Again, the farm orchard and garden usually are small in area and the 

 cost of their protection by some of the simpler methods described further 

 on woiild be slight compared with the returns from protection for a single 

 night at a critical time. 



Frost warnings are issued by the United States Weather Bureau 

 generally about 10 a. m. eastern time. Occasionally, when conditions seem 

 to warrant it, they are issued at other hours. The warnings are tele- 

 graphed to telephone exchanges, which will give the information to their 

 patrons; so that almost any farmer who has a telephone may get the warn- 

 ings by calling his exchange at 11 a. m. or shortly after. The warnings 

 are distributed by mail, also, and are published in the newspapers. 



It must be remembered that these warnings are general in character 

 and cover a large territory. They apply to the average conditions over 

 the territory and not specifically to the individual farm, which, because 

 of its topography or the condition of the soil, may vary greatly from the 

 general average in its liability to frost. Hence, the farmer who expects 

 to obtain the greatest benefit from the warnings should accept them as 

 applying generally to his vicinity, and should make such modification 

 in their application to his own farm as a careful and intelligent study of 

 local conditions seems to warrant. 



FORECASTING FROST FROM LOCAL OBSERVATIONS 



In the present state of knowledge it is hardly possible for one, no matter 

 how well versed in the science of the weather he may be, to forecast frost 

 with a fair degree of accuracy twenty-four hours in advance from observa- 

 tions made at a single place. The frost warnings issued by the United 

 States Weather Biireau are based on several hundred observations taken 

 in all parts of the United States and in Canada. However, local observa- 

 tions are indispensable to an intelligent use of the general warnings and 

 may be made the basis of a fairly accurate judgment for a shorter 

 period than twenty-four hours. Assuming that it is the season when 

 frosts are likely to occur, the points to be considered, aside from local 

 topography, are as follows: 



1. Character of the preceding weather 



2. State of the sky, whether cloudy or clear 



3. Direction and force of the wind 



4. Trend of the temperature 



5. Atmospheric pressure 



