934 



SCIENCE. 



[N. S. Vol. XXIII. No. 599. 



On Positive and Negative Electrons: Pro- 

 fessor H. A. LOEENTZ, of Amsterdam. 



The Elimination of Velocity-Head in the 

 Measurements of Pressures in a Fluid 

 Stream: Professor Francis E. Niphee, 

 of St. Louis. 



Experiments made on a railway train 

 with a Pitot tube show that when the wind 

 blows across the mouth of the tube, the 

 rarefaction produced is greater than the 

 compression when the mouth is directed 

 towards the wind. When the mouth is 

 directed at an angle of 60° with the wind, 

 there is neither compression nor rarefac- 

 tion. "When thus set, a Pitot tube will 

 respond to the actual pressure in a pipe 

 carrying a fluid stream. Velocity effects 

 are eliminated. An improved form of the 

 disk collector previously described by the 

 author was also described and the two col- 

 lectors shown were presented to the society. 

 This collector also eliminates velocity ef- 

 fects. 



Old Weather Records and Franklin as 

 a Meteorologist: Professor Cleveland 

 Abbe, of Washington. 

 This paper emphasizes the fact that some 

 of our earliest weather records are due to 

 the influence of Benjamin Franklin, and 

 that he himself must be recognized as the 

 first of American meteorologists. From 

 boyhood he distrusted the supernatural 

 and the superetitious explanations of nat- 

 ural phenomena. The animus of his whole 

 life was a searching study of the motives 

 of men and the forces of nature. His 

 meteorological work began with a daily 

 record and accompanying explanatory 

 notes. He entertained every plausible 

 hypothesis and tested it by experiment, 

 logic and analogy. His study of the light- 

 ning and thunder-storm by experimental 

 methods, and his study of northeast storms 

 by the collection of reports from all parts 

 of the country (equivalent to the modern 



graphic daily weather map) were but a 

 fraction of his many studies of the atmos- 

 phere. 



The paper collects together some pub- 

 lished and unpublished items illustrative 

 of the great variety of work that Franklin 

 did bearing on meteorology, closing with 

 his study of the cold winter of 1783-^ in 

 Europe, and the prediction (which was 

 perfectly well verified) of the cold winter 

 of 1786-7 in Pennsylvania and New Eng- 

 land. This last effort, based on sound 

 physics and logic, entitles him to be recog- 

 nized as the first long-range forecaster 

 whose methods were in complete harmony 

 with the present state of physical science. 



Was Leivis Evans or Benjamin Franklin 

 the First to recognize that our Northeast 

 Storms come from the Southwest? Pro- 

 fessor William Moeris Davis, of Cam- 

 bridge, Mass. 



In 1747 Lewis Evans, of Philadelphia, 

 prepared a description of the ' Middle Brit- 

 ish Colonies in America,' illustrated by 

 a map, on which, among other explanatory 

 legends, the following statement occurs: 

 'All our great storms begin to leeward; 

 thus a NE storm shall be a day sooner in 

 Virginia than in Boston. ' This brief state- 

 ment has been taken to be the earliest 

 recognition, as it certainly is the first pub- 

 lished statement, of the progressive move- 

 ment of storms, on which the modern art 

 of weather prediction so largely depends. 

 A second edition of the essay and map was 

 published in 1755 ; and as moi'e topograph- 

 ical material had then been collected, the 

 statement concerning storms above quoted 

 was omitted. Evans's publishers were 

 Franklin and Hare, and there is good rea- 

 son for thinking that it was Franklin and 

 not Evans who supplied the statement on 

 the map about storms, along with some 

 account of lightning and electricity; sub- 

 jects which Evans does not treat elsewhere, 



