128 The National Geographic Magazine 



of much scientific difficulty, because 

 of some uncertainty in the elevation of 

 the stations, and the proper temperature 

 argument to be used in making the nee 

 essary reductions. With the lapse of 

 time the necessary observations have 

 accumulated to such an extent that it 

 has become desirable to reduce the entire 

 series taken during the past 30 years to 

 a homogeneous system, with the epoch 

 January r, 1900. Professor Bigelow 

 has been conducting this research for 

 the past two years, and the work is now 

 approaching completion. 



The present investigation has included 

 a complete remodeling of the station 

 elevation data ; the reduction of all the 

 pressures to a normal station pressure, 

 which has never been done before, by 

 the application of a system of corrections 

 for elevation, gravity, instrumental error, 

 and diurnal variation ; the careful de- 

 termination of the temperature gradients 

 in latitude, longitude, and altitude ; the 

 reduction to sea-level by new tables ; 

 the determination of residuals due to 

 local abnormalities, to inaccurate eleva- 

 tions, and to incomplete series of obser- 

 vations, as for those of onl}^ a few years' 

 duration, and the further correction of 

 the station pressures to a homogeneous 

 normal system. 



This work will also contain normal 

 maps of pressure, temperature, and vapor 

 tension on the three following planes : 

 sea-level, 3,500 feet, and 10,000 feet. 

 From these data it will be practicable, in 

 connection with the gradients obtained 

 from the International Cloud Observa- 

 tories, to make good daily weather maps 

 on the three planes above mentioned, 

 and thus to provide further means of 

 studying the behavior of storms and the 

 atmospheric circulation generall}^, at 

 other levels than that of the sea, to 

 which the forecaster is at present con- 

 fined for his predictions. 



Mr. E. C. Barnard presented a plan of 

 work in exploratory surveys. 



Annowncement of Meeting;s. 



March i. — "The Recent Famine in 

 India," by Gilson Willetts. 



J/a;r/^ i-5.— " The Two Ends of the 

 Earth : Peary and the North Pole, and 

 the Cruise of the Bel^ica in the Ant- 

 arctics," by H. L,. Bridgman and Fred- 

 erick A. Cook. 



MavQli 2g. — "Railways and Water- 

 ways of the Russian Empire," by Alex- 

 ander Hume Ford. 



These meetings will be held in the 

 Congregational church, Tenth and G 

 streets northwest, at 8 p. m. 



Technical meetings for the reading of 

 papers and for discussion will be held 

 in the hall of the Cosmos Club Friday 

 evenings, March 8 and 23, at 8 p. m. 



As previously announced, the subject 

 of the afternoon series of lectures for 

 this year is "The Countries of Asia." 

 The dates and lecturers are as follows: 



March 3.— "■ Western Asia," by Tal- 

 cott Williams, EL. D., of the Philadel- 

 phia Press. 



March 12. — "Eastern Asia (China)." 

 Name of lecturer to be announced later. 



March 20. — ' 'Southern Asia (India) . ' ' 

 Name of lecturer to be announced later. 



March 26. — "Northern Asia (Sibe- 

 ria)," by Edwin A. Grosvenor, Profes- 

 sor of Modern Governments in Amherst 

 College. 



^/>rz7^.— "Asia— The Cradle of Hu- 

 manity," by W J McGee, Vice-Presi- . 

 dent of the National Geographic Society. 



These lectures will be given in the 

 Columbia Theatre, Twelfth, and F 

 streets northwest, at 4.20 p. m. 



