696 



SCIENCE 



[N. S. Vol. XXVIII. No. 724 



TBMPEEATUEES OF CAMPUS AND UESA, ICAT, 1908 

 Campus, Messa, 



5,420 ft. 5,835 ft. 



Monthly mean 51.5 54.1 



Mean maximum 60.5 61.0 



Mean daily range 23.2 19.5 



Greatest daily range 39.0 36.0 



Least daily range 0.0 2.0 



Nvtmber of days having minimum 



32 degrees or lower 5.0 2.0 



Date of latest frost May 21 May 5 



For the table above the montbly mean was 

 calculated by averaging the daily means ob- 

 tained by the formula 



(7 A.M. + 2 P.M. + 9 P.M. + 9 P.M.) -J- 4 = Tnean.^ 

 The mean temperature of the mesa station 

 was 2.6 degrees higher than that of the cam- 

 pus; the mean maximum 0.5 degrees and the 

 mean minimum 3.4 degrees higher. It will 

 be noted that the greatest difference is in the 

 mean minimum. The mean daily range is 

 conspicuously less for the mesa than for the 

 campus. To state the case briefly the mesa 

 station has a milder climate than that of the 

 campus; the daily range is less, the mean 

 temperature greater; also for the present 

 year, at least, killing frosts did not continue 

 so late in the season. 



The month of April was warmer than May, 

 but in spite of this anomaly there were about 

 the same differences between campus and 

 mesa. An important point to notice, how- 

 ever, is that the mean maximum was higher 

 at the campus station, 63.8 as against 61.6 on 

 the mesa, but the mean minima show about 

 the same differences as recorded for May. In 

 April, therefore, the campus showed a much 

 more severe climate than the mesa. Days 

 were hotter, nights were cooler. 



Hann states (p. 252) that " in calm weather 

 the valleys are colder than the enclosing 

 mountains, up to a certain height." In the 

 observations made by the writer there was 

 this difference, not only in cahn weather but 

 also in windy weather, indeed, nearly every 

 night the mesa station showed the higher 

 temperature. 



Since the university campus is on the 

 plains, while the mesa is part of the lower 



'Hann, "Handbook of Climatology," Ward's 

 translation, 1903, p. 7. 



foothills, it may be said that the plains have 

 a more severe climate than the lower foot- 

 hills. The writer believes that this difference 

 in climate is an important one in determin- 

 ing the limits of distribution of plants at the 

 tension line between foothills and plains. 

 This question wiU be discussed at length in 

 an article soon to be published in the Univer- 

 sity of Colorado Studies by the present writer 

 and Messrs. G. S. Dodds and W. W. Eobbins. 

 Peancis Eamaley 

 Univeesitt of Coloeado, 

 BoTJiDEE, Colo. 



SOCIETIES AND ACADEMIES 



THE AMEBICAN PHYSICAL SOCIETY 



The fall meeting of the Physical Society was 

 held at Columbia University, New York City, on 

 Saturday, October 24, 1908, with President Edw. 

 L. Nichols in the chair. 



The following papers were presented: 



"Note on Spherical Aberration," W. S. Frank- 

 lin. 



" New Photometric Methods of Studying the 

 Radiating Properties of Various Substances," 

 Edward P. Hyde. 



" Sparking Potentials in a Very High Vacuum," 

 R. A. Millikan. 



" Non-Newtonian Mechanics," Gilbert N. Lewis. 



" The Definition of a Perfect Gas," A. G. Web- 

 ster and M. A. RosanoflF. 



" The Specific Heats of Gases and the Partition 

 of Energy," W. P. Boynton. (By title.) 



" The Distribution of Sound from the Mega- 

 phone," A. G. Webster. 



"The Reflection of Sound by the Ground," A. 

 G. Webster. 



" Thermometric Lag in Calorimetry," Walter P. 

 White. (By title.) 



" The Electromagnetic Mass of a General Elec- 

 tric System," D. F. Comstock. 



" A Study of Electric Wave Vibrators and Re- 

 ceivers," H. W. Webb. 



"ISote on a Method of Determining the Con- 

 centration of the Free Electrons in a Metal," O. 

 W. Richardson. 



" The Kinetic Energy of the Positive Ions 

 emitted by Hot Bodies," F. C. Brown. 



The next meeting of the society will be at 

 Chicago on the Friday and Saturday following 

 Thanksgiving. Eenest Meeeitt, 



Secretary 



