240 



and can not be guarded against, but the former comes from a cooling produced by 

 intense radiation of heat in a clear sky and can be largely protected against. This 

 radiation continues all night, and, as is well known, the coldest moment is just at 

 sunrise, or oftentimes only an hour or two before sunrise, but in that time incalcu- 

 lable mischief may be done. * * * In anticipation of frost the dew-point is the 

 most essential element to be determined. Wheu the air temperature is lowered below 

 the dew-point we are taught that incipient condensation takes place, heat is liberated, 

 and hence the lowest temperature during the night may be taken nearly as the dew- 

 point of the previous evening. If we watch the dew-point of the air from 6 to 9 or 

 10 p. m. and find it steady and above 35" there will be little danger of frost, but if 

 the dew-point is below 32° (freezing) frost may be looked for. [For determining the 

 dew-point, the psychrometer is used. This instrument is described and the method 

 of taking observations with it is explained]. 



Mississippi Station, Bulletin No. 12, June 25, 1890 (pp. 4). 



Cotton-leaf worm. — Practical directious for the application of 

 dry Paris green for the repression of the cotton-leaf worm [Aletia ar- 

 gillacea). 



Nebraska Station, Bulletin No. 15, September 26, 1890 (pp. 41). 



Meteorological report for 1889, De W. B. Brace, Ph. D. (pp. 

 1-14). — This includes the records of daily observations at the univer- 

 sity of temperature, relative humidity, rain-fall, and direction, velocity 

 and total daily movement of wind. Monthly and yearly summaries are 

 also given. The yearly summary is as follows: "Barometer, highest, 

 31.11; lowest, 29.25; mean, 30.083. Temperature, highest, 94°; lowest, 

 —17°; mean, 51.25°. Mean relative humidity, 72.7 ; range of barom- 

 eter, 1.80; range of temperature, 1.11°; greatest daily range of barom- 

 eter, 1.41; greatest daily range of temperature, 45°; total precipitation 

 in inches, 21.83; number of days on which 0,01 or more of rain fell, 63; 

 number of clear days, 153 ; number of fairxlays, 135 ; number of cloudy 

 days, 77; prevailing directions of wind, north and south; maximum 

 velocity of wind, miles per hour, 65 ; total movement of wind, miles, 

 120,255." 



Soil temperatures, 1889, J. G. Smith, B. S. (pp. 15-35). — A de- 

 tailed tabular record of observations with soil thermometers from March 

 to November, inclusive, taken daily at 7 a. m., 12 m., and 6 p. m., at 

 depths of 1, 3, 6, 9, 12, 24, and 36 inches. 



Farm notes, J. G. Smith, B. S. (pp. 37-41). 



Spring wheat and rye. — Brief notes for the season of growth on 4 

 varieties of spring wheat and 1 of spring rye sown at the station on 

 small plats April 8, 1890. '' All gave promise of a good yield, but were 

 cut oft' by hot winds and dry weather at the time the grain was filling." 



Peas, lettuce, and radishes. — Tabulated notes on 14 varieties of peas. 

 Clipper was the earliest maturing variety, but the largest yield was 

 given by Profusion. There are also brief descriptive notes on 16 varie- 

 ties of radishes and 10 varieties of lettuce. 



