398 



NA TURE 



[FeBRUAR\ 2 2. 1894 



treatise emiiled " Experiments in Aerodynamics." Interesting 

 results have since been reached, which appear to be of wide 

 utiliiarian importance, but though Prof. Langley hopes soon to 

 be able to make some communication of them to the public, 

 they are not yet complete. In this same connection, in pursuit of 

 an investigation begun some years ago, he has made experi- 

 ments upon the variations cominually going on in the atmo- 

 sphere, in what is regarded for ordinary meteorological purposes 

 as a steady wind. Specially light anemometers have been con- 

 structed and mounted upon the north tower of the Smithsonian 

 building, and connected with a suitable recording apparatus. 

 The complete resuils, which promise conclusions of practical 

 importance, are being collated and will be published at a later 

 date. (See Nature, January 18.) 



The extensive invesiiga ions carried on in astro-physics are 

 referred to in the adjoining column. 



As in previous yt-ars, aid to a limited extent has been given 

 to original investigators who are not immediately connected 

 with the Institution. Prof. E. W. Morley has coniinued his 

 determinations of the density of oxygen and hydrogen, for which 

 special apparatus has been provided by the Institution. 



A paper by Prof. A. A. Michelson, upon the " Application 

 of interference methods to spectroscopic measurements," with 

 a view to increased precision in measuring specific wave- 

 lengths of light, has been published in connection wiih his work 

 upon a universal standard of length. Mr. F. L. O. Wadsworth 

 was detached from the observatory staff, and sent (at the 

 expense of the Smithsonian lund) to the Bureau Internationale 

 des Poids et Vlesu res, near Paris, to assist Prof. Michelson during 

 a stay of six weeks in preparati >n of this standard. 



The Hodgkins Fund. 



Numerous applications, which are referred to the advisory 

 cominiitee for considera'ion, have already been made for grants 

 from the Hodgkins Fund to aid original investigations upon the 

 nature of atiuo-^pheric air and its properties. Two have been 

 approved, a jjrant of 500 dollars havrng been made to Dr. O. 

 Lummer and Dr. E. Pringsheim, members of the Physical 

 Institute of the Berlin Universi'y, for researches on the deter- 

 mination of an exact measure of the cooling of gases while 

 expamlinsj;, with a view to revising the value of that mo^t im- 

 portant constant which is technically termed the "gamma" 

 function. I irs. Luminer and Pringsheim were recommended 

 for this work by Dr. H. von Helmholiz, of Berlin. 



A second grant of 1000 dollars has been made to Dr. J. S. 

 Billings, U.S A., Army Medical Museum, Washington, and to 

 Dr. Weir Mitchill, of Philadelphia, for an investigation into 

 the nature of the peculiar sut)stances of organic origin comained 

 in the air expired by human beings, with a specific reference to 

 the practical applicaiion of the results obtained to the problem 

 of ventilation for inhabited rooms. 



The Naples Table. 

 In the spring of last year, a petition, signed by nearly two 

 hundred bi. ilogists, who represented some eighty universities 

 and scientific institutions, was presented to Prof. Lanjiley, ask- 

 ing that a table he maintained by the Smithsonian Institution at 

 the Naples Zoological Station, for the benefit of American 

 invesiigaiors. This step was favourably decided upon, and in 

 April last an advisory committee was appointed, at Prof. 

 Langle\'s request, in onler to obtain opinions as to the best 

 administration of the table. The four members of this com- 

 mittee are :— Major John S. Billings, U.S A., nominated by 

 Prof. O. C. Marsh, President of the National Academy of 

 Sciences; Dr. E. B. Wilson, Professor ol Zoology, Columbia 

 University, nominated by Prof. Chittenden, President of the 

 Society of American Na uralists ; Dr. C. W. Stiles, Zoologist, 

 Bureau ot Animal Industry, U.S. Department of Agriculture, 

 nominated by Prof. C. O. Whitman, President of the American 

 Morphological Society; Dr. John A. Ryder, Professor of Em- 

 bryology, University of Pennsylvania, nominated by Prof. 

 Allen, President of the Association of American Anaiomists. 

 Dr. J. S. Billings, U.S.A., has been designated chairman, and 

 Dr. C W. Stiles secretary of the committee. 



Satisfactory conditions as to the occupancy of the table have 

 been arranged with Dr Dohm, the director of the station at 

 Naples, and a contract has been signed and completed. 



Numerous applications for the occupancy of the table have 

 been received, but at the close of the fiscal year sufficient con- 

 sideration had not been given them to render it possible to 

 jnake any definite assignment. 



NO. T269, ^^'^- 49] 



The Astro- Physical Observatory. 



Prof. Langley has continued his important investigations 

 with the bolometer. The instrument, as now constructed, is a 

 minute strip of metal barely 7,^^ of an inch wide, and less than 

 ifo^Tnrof an inch thick. Through this frail thread of metal a cur- 

 rent of electricity is continually kept flowing. When the spectrum, 

 visible or invisible, is thrown upon it, the thread is warmed and 

 the current decreased by an amount corresponding to the in- 

 tensity of the effect received, while novel instruments specially 

 mounted and constructed are in electric connection with the 

 thread, and now automatically record every minute change in 

 this current. 



With late improvements these instruments are so delicate 

 that a change of temperature of one-millionth of a degree is 

 readily detected and even measured, and it is easy to see that 

 as a consequence of this delicacy the greatest care must be taken 

 in their use. Thus the laboratory must be almost completely 

 darkened, and closed tightly, so as to exclude all draughts and to 

 keep it at as nearly a uniform temperature as possible, while 

 for other reasons it must be kept under constant hygrometric 

 conditions. 



In spite of numerous difficulties, most of which are due to 

 the very temporary and inefficient nature of the small wooden 

 building in which the work is carried on, and its proximity to 

 the traffic-laden streets, the expectations of last year have been 

 largely realised, and a detailed publication of the work, accom- 

 panied by charts showing several hundred new and before un- 

 known lines, will shortly be issued. 



The result of the year's work has been the discovery and 

 approximate determination of position of about 150 or 200 new 

 lines in the hitherto unexplored region of the solar spectrum. 

 Important as these results are, they are but the beginning of 

 of what Prof. Langley hopes will be accomplished. 



In addition to the bolometric work proper, experiments on 

 three special methods of investigation of the infra-red spectrum 

 have formed a considerable portion of the year's work : — -(i) 

 Preliminary experiments on the measurement of wave-lengths 

 in the invisible spectrum by interference methods. (2) Experi- 

 ments on photographing the invisible spectrum by the aid of 

 phosphorescent films. (3) Preliminai'y experiments on bolo- 

 metric investigation of the infra-red normal spectrum. What 

 might almost be said to have been the chief work of the 

 observatory for the year, has been the improvement of the 

 apparatus and instrumental conditions of working. 



Lttnar Photography. 



Prof. Langley has been interested for a considerable time 

 in the possibility of preparing a chart of the moon by photo- 

 graphy, which would enable geologists and selenographers to 

 study its surface in their cabinets with all the details before 

 them which astronomers have at command in the use of the 

 most powerful telescopes. Such a plan would have seemed 

 chimerical a few years ago, and it is still surrounded with 

 difficulties, but it is probable that within a comparatively few 

 years it may be successfully carried out. No definite scale has 

 been adopted, but it is desirable that the disc thus presented 

 should approximate in size one two-millionth of the lunar 

 diameter ; but while photographs have been made on this scale, 

 none of them show detail which may not be given on a smaller 

 one. 



The work has been favoured with the co-operation and 

 interest of the directors of the Harvard College Observatory, 

 of the Lick Observatory, and others, who in response to a letter 

 ad<iressed to them on February 10, 1893, have furnished many 

 valuable suggestions. 



The preparation of a series of en'argements of lunar photo- 

 graphs taken at the Kenwood and Lick Observatories, has been 

 undertaken at the Astro- Physical Observatory. Some attempts 

 at solar photography have been made at this observatory, but 

 the atmospheric conditions prove to be very unfavourable to 

 any satisfactory work in this direction. 



The National Mtiseiim. 

 The National Museum suffers from the want of funds for the 

 improvement of the collections by purchase. It is pointed out 

 that in respect of this provision, the museum stands at the foot 

 of all American museums, being surpassed evtn by every 

 municipal museum of note in the United Siates. The 

 disadvantage in which it stands (Prof. Langley remarks), when 

 compared with what are now its competitors in the national 



