September 26, 1890.J 



SCIENCE. 



179 



LETTERS TO THE EDITOR. 



*+* Correspondents are requested to be as brief as possible. Tlie luriter's name 

 is ill all cases reqitired as proof of good faith. 



The editor will he c/lad to p '.dtlish any queries consonant with the character 

 of the journal. 



Onreqnpst. t'centy copies of the number containing his eoniniunicatiomvill 

 be furnished free to any correspondent. 



The Rotatory Motion of Heated Air. 



Noticing that Professor Hazen questions, in Science, the rota- 

 tory theory of tornadoes, il occurs to me to publish an observation 

 that I recently made, which may have some bearing on this sub- 

 ject. Not long ago, while watching the surface of a cup of hot 

 tea, which contained some sugar, but no milk or cream, my atten- 

 tion was attracted to the phenomena presented on its surface. Close 

 to the hot liquid, and covering it quite evenly,,was a thin layer 

 of condensed vapor. The air of the room was still, and I pro- 

 tected the Kim from my bx-eath, as I watched it. I saw the film 

 in constant motion. At one or two points at a time the vapor 

 acquired two motions, — one in a whorl, and one progressive. In 

 the former the motion was first visible at the exterior, in a circle 

 a little more than half an inch in diameter. The broad part of 

 each ray of the whorl appeared first, and afterward the parts near 

 the focus wtre developed, and were rotated or twisted round the 

 focus at a relatively rapid rate. As this took place, the whole 

 whorl advanced across the surface of the liquid until the whorl 

 disappeared, and the clear surface appeared without any film 

 above it. Sometimes only one whorl was in sight, sometimes two 

 aijpeared at once. This phenomenon was repeated until no more 

 vapor was visible above the liquid. 



As it appeared to me, there were here conditions favorable to 

 observing the behavior of moisture-laden air over a super-heated 

 level surface. Some condition which escaped notice must have 

 determined the point at which a special motion was initiated; 

 but the uniformity with which this developed into a centripetal 

 rotatory and advancing movement was quite impressive. How 

 far the conditions of the observation coincide with the conditions 

 present in tornadoes, those who are competent to discuss meteoro- 

 logical questions may decide. ^haeles W. Dulles. 



Philadelphia, Sept. 20. 



AMONG THE PUBLISHERS. 



"The Essentials of Medical Chemistry and Urinalysis," by 

 Sam E. Woody, M.D., published by P. Blakiston, Son, & Co., has 

 reached a third edition, which would indicate that the book, 

 which is small, is filling ils place. 



— Another characteristic brochure by Professor Henry Drum- 

 mond, under the title of "Perfected Life, the Greatest Need of 

 the World," has just been issued uniform with the jwpular booklet 

 " Love the Supreme Gift, or the Greatest Thing in the World." 

 Both aie published by Fleming H. Revell, New York and Chicago. 



— We have received from Messrs. Dauchy & Co 's Newspaper 

 Advertisement Agency, 27 Park Place, New York, their "New Cata- 

 logue of American Periodicals," a volume of 634 pages. It con- 

 tains a list of all newspapers, magazines, and other periodicals in 

 the United States and Canada which insert advertisements, and is 

 corrected up to Aug. 15 of this year. 



— Messrs. Jlacmillan & Co. have just issued "The Parabola," 

 being Part I. of "Geometrical Conies," by Rev. John J. Milne 

 and R. F. Davis. Instead of foUovring the usual plan, the authors 

 have endeavored to make a continuous treatise as distinguished 

 from a series of detached propositions. At the close of the book 

 is a valuable collection of problems. 



— Dr. Charles M. Andrews of Bryn Mawr College will publish 

 in the October number of the Aimals of the American Academy of 

 Political and Social Science an interesting article on "Beginnings 

 of the Connecticut Towns." The Constitution of 1689 has a wider 

 than local interest, since it was the first written constitution, the 

 prototype of Republican government on this continent. It is a 

 question of no small importance, therefore, whether the Constitu- 

 tion was founded by the towns as such or by the people. This is 

 the question discussed by Dr. Andrews. A painstaking study of 



the facts leads him to the conclusion, in opposition to the late 

 -•Alexander Johnston and many others, that Connecticut draughted 

 its organic law on the theory "that the sovereignty of a State is in 

 the people of that State." 



— Another example of the rapid growth of chemical literature 

 is shown in the appearance from the press of John Wdey & Sons 

 of "Sugar Analysis," by Ferdinand G. Wiechmann, Ph.D. Dr. 

 Wiechmann is instructor in chemical physics and chemical phi- 

 losophy at the School of Mines, Columbia College, and is consult- 

 ing chemist to the Havemeyers & Elder Sugar Refinery Company 

 of Brooklyn. The work is intended as a handbook of instruction 

 in schools of chemical technology, and for use in the refineries, 

 sugar-houses, and experiment stations. Within the past few 

 years many changes have been introduced in the methods of sugar 

 analysis, and new methods have been devised, and, as is usual 

 with such matters, the literature is scattered through numerous 

 foreign journals. It has been Dr. Wiechmann's purpose to bring 

 this new matter together into such shape as to make it available 

 for those directly interested. The methods of analysis which he 

 has selected from the vast wealth of material available have been 

 chosen after long trial and practice under the supervision of the 

 author. Instead of taking up for discussion, as is usual, the 

 different products met with in sugar laboratories, such as raw 

 sugars, refined sugars, liquors, molasses, etc., and describing for 

 each in turn the determination of their constituents, the author 

 has deemed it more expedient to discuss the methods of deter- 

 mining the individual constituents, as sucrose, invert sugar, 

 water, ash, etc., independently of the products in which they may 

 occur. He believes that by the adoption of this plan repetitions 

 have been avoided. Examples have been inserted in the text to 

 aid in the understanding of the principles discussed, and of the 

 calculations. As is usual with such works, various references to 

 original memoirs are given. The book is furnished with numer- 

 ous tables, as is required in such a subject. 



— The twentieth anniversary of I'he Century is celebrated by 

 the publication of the next (November) number. 2'he Century 

 series of separate illustrated papers cm the movement to California 

 in 1849 and the events which preceded it, begins in the November 

 number with a narrative, by Gen. John Bidwell, of the experi- 

 ences of the first emigrant train to California. There is no part 

 of the world, of equal civilization, of which so little has been di- 

 vulged as of Thibet. A well-qualified American traveller, Mr. W. 

 Woodville Rockhill, has recently returned from a journey through 

 this the unknown heart of Asia, and will give in a series of illus- 

 trated papers the results of his travels and observations. For 

 seven hundred miles of Mr Rockhill's journey he passed through 

 a country where no white man had ever set foot. Among the 

 articles promised are some on "The Personal Traits of Lincoln," 

 "Adventures of War Prisoners," "Minister Dallas at the Court of 

 the Czar Nicholas," "Indian Fights and Fighters," "American and 

 English Frigates in the War of 1812," " 'The Faith Doctor' " (by 

 Edward Eggleston), "Mmes. De Stael, Roland, and Recamier," 

 "Pictures by American Artists," "American Newspapers," "Mu- 

 nicipal Government in Europe and America," and "Present Day 

 Papers." This last unique series of well-considered utterances by 

 prominent writers, on the great questions of the day, will be con- 

 tinued during the coming year. The group has recently added to its 

 own number, and now consists of the following: Charles W, Shields, 

 Hugh Miller Thompson, Henry C. Potter, Charles A. Briggs, The- 

 odore T. Munger, Washington Gladden, William Chauncey Lang- 

 don, Francis G. Peabody, Samuel W. Dike, William F. Slocum, 

 jun., Seth Low, Edward J. Phelps, Richard T. Ely, William J. 

 Sloane, and Charles Dudley Warner. The above list gives only a 

 part of the contents of the new year, special announcements of 

 features in preparation being reserved. Mr. George Kennan, who 

 was interrupted in the preparation of his concluding papers, will, 

 it is expected, before long give further chapters of the story of his 

 travels in Siberia and Russia ; Mrs. Van Rensselaer will publish 

 her final papers on English cathedrals; and Mr. La Farge will 

 give his views of art in general, and especially of modern and 

 Western art methods, from the point of view of an Oriental resi- 

 dence. 



