June 4, 1886.] 



SCIENCE. 



503 



jet to break easily under the influence of moderate 

 impulses. 



The foregoing is ttle more than the outlines of 

 a new theory of jet-vibrations. The author hopes 

 to supply in the future further experimental evi- 

 dence in support of it. 



BOSTON LETTER. 



Evidently one should join the Essex institute 

 in Salem if one wishes to live to a green old age. 

 This well-honored scientific body held its annual 

 meeting recently : and the secretary's report 

 showed, that, of the 24 deaths during the year, 

 all but one were of persons over fifty years of age. 

 Moreover, of the 324 living members, two-thirds 

 are over threescore years and ten, and seven are 

 past fourscore. The institute is soon to go into 

 new quarters. 



Preparations are making for the celebration at 

 Cambridge of the two hundred and fiftieth anniver- 

 sary of the founding of Harvard college. It will 

 not take place at the commencement season, but 

 at some time the following autumn, and it seems 

 to be generally understood that Hon. James Rus- 

 sell Lowell will preside. It will be a different 

 thing from the bicentenary, when a smaller 

 audience-room than is now available permitted 

 even all the undergraduates to find a place. The 

 living Harvard alumni alone are probably three 

 times the number living fifty years ago, and cer- 

 tainly the undergraduates are five times as nu- 

 merous as then. This event makes specially ap- 

 propriate the list just published by the university, 

 showing the literary activity of its officers during 

 the last five years. A similar ten-years list was 

 published in 1880 ; but the present, though only for 

 half that time, not only contains a longer list of 

 publications than the former, but a somewhat 

 larger number of writers among the officers. 



Gifts continue to come in to the university. 

 Mrs. Draper of New York continues to further 

 the researches to which the late Dr. Henry 

 Draper devoted his life. Her latest gift is of a 

 thousand dollars to Harvard college observatory, 

 to be expended under the direction of Professor 

 Pickering in prosecuting researches in the pho- 

 tography of stellar spectra ; the eleven-inch pho- 

 tographic lens constructed by Dr. Draper will be 

 employed in this work, and those who heard Pro- 

 fessor Pickering's account, at the Albany meeting 

 of the National academy last autumn, of his own 

 work in the field in which Dr. Draper's name is 

 so honorably associated, will believe that Mrs. 

 Draper has made an excellent choice. 



In this same connection it should be mentioned 

 that the contest at law about the Paine bequest to 



the Harvard observatory, mention of which has 

 before been made in this correspondence, is hap- 

 pily closed by amicable settlement between the 

 parties concerned. The amount which will now 

 be turned over to the observatory, probably with- 

 in the next month or two, will scarcely differ 

 from that previously announced, and on the 

 death of the widow it is probable that the entire 

 bequest will exceed three hundred thousand dol- 

 lars. Those who have followed the telling activ- 

 ity of the observatory under its present manage- 

 ment will be confident that no other institution 

 could make better use of such a noble gift. 



At the annual meeting of the American acad- 

 emy, May 25, it was voted to present the Rum- 

 ford gold and silver medal to Professor Langley 

 of the Allegheny observatory, for his researches 

 in radiant energy. Thus Professor Langley has 

 in a single year borne off the two principal gold 

 medals given for scientific work in America, hav- 

 ing received the Draper medal of the National 

 academy only last month. No one will dispute 

 his right to them. The Rumford fund will also 

 be used this year by the American academy in 

 aid of researches upon the solar corona at the 

 time of the total eclipse of August next, five hun- 

 dred dollars having been appropriated in aid of 

 Mr. W. H. Pickering's expedition to the West 

 Indies. A letter was read from Mr. Greenough 

 the sculptor, a fellow of the academy, announcing 

 his gift to the academy of a portrait of Galileo, 

 which he stated was either an old copy or a replica 

 of the portrait in the Pitti palace. The portrait is 

 already on its way to America. 



In passing through Mount Auburn cemetery 

 the other day I observed for the first time the 

 monument which has been erected at the grave of 

 Pourtales, the colleague of Agassiz, and the pio- 

 neer in the zoology of the deep seas. It is a simple 

 but massive semicircular slab of very fine-grained 

 sandstone, on one face of which is the usual in- 

 scription, while on the other, facing the grave, 

 has been deeply engraved a conventionalized Pec- 

 ten-like sea-shell, forming a sort of niche ; and on 

 the surface of this are neatly sculptured in bas- 

 relief a coral, a Coma tula, a Gorgonia. and a 

 magnified foraminifer, emblematic of the subjects 

 of his study. 



Ths topographical field-parties of the U. S. 

 geological survey have begun their season's opera- 

 tions in this state, and before next winter most of 

 the field-work will have been finished. The Ap- 

 palachian mountain club, taking advantage of the 

 work already completed, is about to issue, by per- 

 mission of the survey, a photolithograph of a 

 portion of the field-sheets on the original scale, 

 comprising the extreme north-western corner of 



