AnnOTT LAWRENCE ROTCH. Sll 



when lio carried out a scries of comparisons hetwoen the sling ther- 

 mometer and Assmann's aspiration thermometer. He was a meml)er 

 of more than one sohir cchpse expedition. His studies of eclipse 

 meteorology are among the most complete which have been made. 

 Among his many contributions to tlu' advancement of meteorology 

 must also be mentioned his invention of an instrument for determining 

 the true direction and velocity of the wintl at sea. 



Professor Rotch was naturally intensely interested in the recent 

 rapid development of aeronautics. His earlier training at the Massa- 

 chusetts Institute of Technology, and his untiring zeal in the explora- 

 tion of the upper air, combined to give him this interest. He turned 

 his attention largely in that direction of late years. It was character- 

 istic of him that, not content with the mere collection of data, and with 

 investigations of theoretical interest, he always strove to make these 

 results of practical use. Thus, soon after the establishment of his 

 observatory, the issue of local weather forecasts Avas begun, and one of 

 the last things which he published (in association with Mr, A. H. 

 Palmer) was a set of "Charts of the Atmosphere for Aeronauts and 

 Aviators" (1911), a pioneer work, embodying many of the results 

 of observations made at Blue Hill in a practical form for the use of air- 

 men. 



Professor Rotch originally suggested the issue of a cyclostyle weather 

 map, and himself paid the expenses of the first publication of such maps, 

 which was on May 1, 1886, at the Boston office of the United States 

 Signal Service, Sergt. O. B. Cole, who was then in charge of the station, 

 cooperating in the undertaking. This was the first printing of a synop- 

 tic chart outside of the Central Office at ^Yashington, and the Signal 

 Service soon extended this method of issuing maps to several of its 

 other stations. The local weather predictions were first made at 

 Blue Hill on July 1, 1886. Their superiority over the Washington 

 predictions made by the Signal Service was soon apparent, and in 

 Februar\', 1887 (American Meteorological Journal), Professor Rotch 

 suggested that the United States Signal Service "discontinue its 

 Washington predictions by having the district indications made at 

 the chief station of each district by a competent person and from 

 the data of the synoptic charts." This plan was soon thereafter 

 adopted by the Signal Service at Boston, and was later generally 

 extended over the country. 



Forecasts made at Blue Hill were first published in the Boston 

 Evening Transcript from January 4, 1887, until March 7, 1887. From 

 May 2, 1887, until April 30, 1888, and from Jamuiry 1, 1889, until 



