236 



SCIENCE. 



[N. S. Vol. XVII. No. 423. 



system for the United States, Canada and the 

 West Indies ; a discussion of the vapor tension 

 observations throughout the United States; a 

 study of wind velocities and fluctuations of 

 water level on Lake Erie, and of eclipse me- 

 teorology and allied problems. 



The ' Report ' also contains, besides the 

 usual tables, tables showing the highest and 

 lowest temperatures recorded at Weather Bu- 

 reau stations for each month of the year, 

 from the beginning of observations until the 

 end of 1901 (with charts) ; the monthly and 

 annual mean relative humidity for all Weather 

 Bureau stations (with charts), etc. 



SIMILAK BAROMETRIC VARIATIONS OVER LARGE 

 AREAS. 



Sir Norman Lockyer and Dr. W. J. S. 

 Lockyer, in England, and Professor E. H. 

 Bigelow, in this country, have lately been in- 

 vestigating the similarity of curves represent- 

 ing many solar and meteorological phenom- 

 ena. Several papers on this subject have 

 already been published. In Nature for Jan- 

 uary 8, Dr. Lockyer presents some of his 

 latest results. The curves showing the vari- 

 ations in pressure at Bombay, Colombo, Ba- 

 tavia, Mauritius, and Perth Adelaide and 

 Sydney, Australia, are strikingly similar 

 and indicate that the same kind of variations 

 are in action over the whole region. The 

 curves for Cordoba, Mobile, Jacksonville, 

 Pensacola and San Diego, and the inverted 

 curve for Bombay are also very similar to 

 one another. Here, then, are two large areas 

 indicating similar barometric variations from 

 year to year, but one showing an excess while 

 the other displays a deficiency. Professor 

 Bigelow has also come to the conclusion 

 {Monthly Weather Review, XXX., 347) that 

 the same pressure variations prevail over very 

 large areas, but that they vary from one dis- 

 trict to another. Dr. Lockyer points out that 

 the two investigations agree as to the follow- 

 ing points: (1) The close connection between 

 solar activity and barometric pressure; (2) 

 the great extent over which veiy similar pres- 

 sure variations exist, and (3) the presence of 

 two large areas, the pressure variations over 

 which are the reciprocal of each other. 



WINTER ARIDITY INDOORS. 



The dryness of the air in furnace-heated 

 houses is attracting more and more attention. 

 In Science for March 23, 1900 (N. S., Vol. 

 XL, 474), reference was made in these Notes 

 to some observations of relative humidity 

 made by the undersigned in his study during 

 three weeks of November, 1899. In the 

 Journal of Geography for December last. Pro- 

 fessor Mark S. W. Jefferson, under the title 

 ' Winter Aridity Indoors,' presents a simple 

 mathematical treatment to show the actual 

 quantities of water demanded in connection 

 with a heating and ventilating plant to pre- 

 serve a healthful humidity within doors in 

 winter. Professor Jefferson concludes that, 

 under the average conditions of temperature 

 and humidity indoors during the three weeks 

 referred to above, about two gallons of water 

 per individual should be evaporated to hu- 

 midify the daily supply of air. > Such obser- 

 vations as these naturally suggest a useful 

 line of work in connection with giving the 

 air from our furnaces a proper supply of 

 moisture. 



NOTES. 



The rapid advance of balloon and of kite 

 meteorology is evidenced by the fact that a 

 new meteorological station has been estab- 

 lished at Viborg, in northern Jutland, for the 

 express purpose of carrying on the investiga- 

 tion of the free air by means of kites and 

 balloons. This station is maintained through 

 the cooperation of Erench, Swedish and Dan- 

 ish meteorologists. The location is an ad- 

 mirable one, being in a district where storms 

 are frequent. Twenty-eight persons consti- 

 tute the force at the new observatory, in 

 whose establishment Messrs. de Bort, Hilde- 

 brandsson and Paulsen have been chiefly con- 

 cerned. E. DeC. Ward. 



ELECTRICALLY UTILIZED POWER AT 

 NIAGARA FALLS. 



Recent Consular Reports include one from 

 Consul H. W. Brush, at Niagara Ealls, On- 

 tario, Canada, on the development of hy- 

 draulic power from the great falls. The orig- 

 inal development of 50,000 horse-power on 



