Academy of Science. 89 



It will be observed that for medium and high velocities the two methods com- 

 pared very well, and for low velocities, as intimated, the anemometer fails to give a 

 large enough record. Besides showing that the apparatus at Lawrence can not reg- 

 ister too much, my observations have convinced me that tlie method is one which 

 may be of value to meteorologists. From its extreme simplicity and lightness, the 

 instrument may be easily earned from place to place by traveling observers, and a 

 record of the wind's velocity at any station can be obtained in a few minutes. As a 

 check upon another instrument it may be used to advantage as just shown. The 

 dimensions which I have given are larger than necessary. I chose them in order to 

 have the copper ball on a level with the cups of the anemometer. 



METEOROLOGICAL SUMMARY FOR 1877. 



Prof. F. H. Snow's Annual Report as Meteorologist to the State Board of 



Agriculture. 



Station: Lawrence. Kansas. Latitude, 38° 57' 25"; longitude, 95° 15'; elevation of barometer and 

 thermometers, 875 feet above the sea level, and five feet above the ground; rain gauge on the ground; 

 anemometer, 105 feet above the ground, on the dome of the University building, 1,200 feet above the 

 sea level. 



The chief characteristics of the weather of 1877 were the large and well-distrib- 

 uted rainfall, the low temperature of the summer months, the high temperature of 

 the winter months, the unusual degree of atmospheric humidity, and the compara- 

 tive lightness of the winds. 



TEMPERATURE. 



Mean temperature of the year, 54°. 16, which is 1°.33 above the mean of the nine 

 preceding years. The highest temperature was 99°, on the 7th of July; the lowest 

 was 9° below zero, on the 16th of January, giving a yearly range of 108°. Mean tem- 

 perature at 7 A. M., 48°.54; at 2 p. m., 63°. 50; at 9 p. m., 52°. 81. 



Mean temperature of the winter mouths, 36°. 56, which is 7°. 71 above the average 

 winter temperature; of the spring, 52°.81, which is 0°.02 above the average; of the 

 summer, 73°. 75, which is 2°.86 below the average; of the autumn, 53°.54, which is 

 1°.20 above the average. 



The coldest month of the year was January, with a mean temperature of 25°. 60; 

 the coldest week was January 7th to 13th, with mean temperature, 17°.49; the cold- 

 est day was January 12th, with mean temperature, 3°. 2. The mercury fell below 

 zero but three times, all of which were in January. 



The warmest month of the year was July, with a mean temperature of 75°. 13; 

 the warmest week was July 2d to 8th, with mean temperature 82°. 64; the warmest 

 day was July 7th, with mean temperature, 86°. The mercuiy reached or exceeded 

 90° on only twenty days, viz: four in June, eight in July, seven in August, and 

 one in September. 



The last light frost of spring was on May 1st ; the first light frost of autumn was 

 on October 4th, giving an interval of 156 days entirely without frost. The last 

 severe frost of spring was on April 2d ; the first severe frost of autumn was on 

 November 5th, giving an interval of fully seven months, or 217 days, without severe 



