MAKING THE OBSERVATIONS 23 



Making local observations. 



The value of climatic information, supplied by the Weather Bureau, 

 may be enhanced greatly by observations of temperature and rainfall 

 made on the farm, particularly if made in connection with phenological 

 observations suggested on pages 17-19. Such a record is a valuable 

 asset to a farm, and its value increases as each year's record is added. 

 A suitable equipment need not be expensive, nor the work made la- 

 borious. The highest and lowest temperature may be obtained at a 

 single reading, made preferably about sunset, by use of Six's pattern 

 of maximum and minimum thermometers, mentioned on page 1. The 

 average of the two thermometer readings gives the daily mean. 

 This is the method used by the Weather Bureau, and wiU make the 

 record strictly comparable with any data obtained from that source. 



A serviceable rain-gauge may be constructed by the use of any vessel 

 having straight sides. A tomato-can, placed two feet above ground, 

 and fifty feet from buildings or trees, will give good results. The 

 depth of the water caught may be measured with an ordinary rule, but 

 to make the record comparable with those made by the Weather Bureau, 

 the fractions of an inch should be reduced to decimals. Perhaps it 

 would be better to make a rule graduated in inches and tenths. 

 Ten inches of average snow will make, when melted, one inch of water. 



A convenient method for recording and preserving weather obser- 

 vations is important. A book is preferable, having at least thirty-four 

 ruled lines. Use one page for each month. Rule the page into eight 

 columns, leaving ample margin on the right for phenological notes. 

 Beginning at the left, head the columns as follows : date ; highest tem- 

 perature ; lowest ; mean ; rainfall ; snowfall ; wind direction (every 

 farm should have a good weather-vane) ; weather; phenology. Enter 

 each day's record on line with appropriate date. Under phenology 

 full notes should be made, showing the condition and advancement of 

 the various crops, for here is the point of contact between current 

 weather and plant growth. All this may be combined with a diary 

 of farm work. At the end of each month the temperature columns 

 should be averaged and the total rainfall set down ; and when these 

 values are compared with the normal, the importance of the climatic 

 factor in crop production will be more fully understood. (For ther- 

 mometer scales, see Chap. XXVII.) 



