5 66 



NA TURE 



[October 28, 1922 



That architects are not entirely indifferent to this 

 subject is shown by the fact that on the formation oi 

 the Department of Scientific and Industrial Research 

 several years ago, the Royal Institute of British 

 Architects formally directed attention to the need for 

 acoustic experiments, associated with design and 

 construction. 



This need is recognised elsewhere, as is evidenced by 

 the work done in America where, at Geneva, Illinois, 

 in the laboratory of acoustics built for the late Prof. 

 Sabine by Col. Fabyan, much valuable' research has 

 been carried out. Before his death in 1919 at the age 

 of fifty, Prof. Sabine had collected a great deal of 

 experimental data on sound in relation to materials, 

 and his researches had sufficiently impressed themselves 

 on American architects more than twenty years ago 

 to result in consultations on acoustic design. The 

 laboratory is now under the direction of Prof. Paul E. 

 Sabine, some of whose recent researches are referred 

 to elsewhere in this issue with a brief description of 

 his laboratory. In this building, devoted solely to 

 acoustic problems, the difficulties of adequate sound 

 transmission and suppression are constantly being in- 

 vestigated. Work of this nature must eventually prove 

 a valuable national asset by preventing wasted effort 

 and expenditure, and the example of America is worth 

 serious consideration in this country. 



There are a great many problems in which the work 

 of the man of science can materially assist the architect, 

 not only in acoustics but also in the use of materials 

 for construction generally, but if science is to have its 

 due appreciation it must supply information of a 

 practical and simple kind which will appeal to workers 

 in a field already so wide that they have little time for 

 the study of theory, however interesting. 



The Body Temperature of Birds. 



A Study of the Body Temperature of- Birds. Bv 

 Alexander Wetmore. Smithsonian Miscellaneous 

 Collections, Vol. 72, Number 12. (Washington, 

 D.C., U.S.A. : Smithsonian Institution.) 



WITH regard to body temperature, animals are 

 divided into two great groups, namely, warm- 

 blooded and cold - blooded, the former including 

 mammals and birds, the latter reptiles, amphibians, 

 fishes, and all invertebrates. A more accurate distinc- 

 tion than the actual temperature, however, is based 

 on the fact that the so-called warm-blooded animals 

 have a constant temperature (homoiothermal) while 

 the cold-blooded animals have a variable temperature 

 which is practically the same as that of the environ- 

 ment in which they live (poikilothermal). 

 NO. 2765, VOL. I IO] 



The essential difference between these two groups 

 is. that homoiothermal animals — mammals and birds 

 — possess a heat-regulating mechanism by means of 

 which the heat production and heat loss are so balanci d 

 that the body temperature remains practically constant, 

 while poikilothermal animals — all others, except 

 mammals and birds — possess no such mechanism. 



Although much time and research have been 

 devoted by a host of investigators to the stud; 

 body temperature and heat production in mammals, 

 comparatively little attention has been given to this 

 field in avian physiology, and all interested in this 

 much-neglected subject will be greatly indebted to 

 the author of the above monograph for his important 

 and valuable contribution. 



The investigation covered a period extending from 

 January 1912 to October 1919, and records were 

 obtained from 1558 individuals of 327 species of birds 

 distributed among 50 families. It was carried on 

 within the limits of the United States of America, 

 and all the year round, in temperate regions where 

 the extreme cold of winter is not encountered. In 

 addition to the 327 species examined by the author 

 personally, the previously published records from 89 

 others are given in the form of a supplementary table, 

 so that definite statements may be found in the work 

 regarding the body temperature of 416 species of birds. 

 A table giving the individual records in detail, not 

 included because of the high cost of printing, is de- 

 posited in the files of the Smithsonian Institution of 

 Washington, and may be consulted by those interested. 



Specially constructed thermometers of the clinical 



type but with a wider range — 95 F. + to 1 15 3 F.H 



were used. When a bird was shot a temperature 

 reading was taken from the large intestine reached 

 through the anus or from the proventriculus through 

 the mouth, only when the specimen could be secured 

 immediately. If there was any delay in retrieving a 

 correct reading could not be made, so that it was only 

 possible to secure records from less than half the birds 

 collected. In the short time that intervened between 

 the shooting and introduction of the thermometer, it 

 is assumed that no appreciable loss of heat from the 

 body took place, and that the figure recorded indicates 

 the temperature immediately before death. 



With regard to the diurnal rhythm of body tempera- 

 ture found in all homoiothermal animals, including 

 man, the author was able to corroborate the work of 

 previous observers, and it is particularly interesting to 

 note that in nocturnal birds, such as owls, the normal 

 rhythm is reversed, the temperature being highest 

 during the night (period of activity) and lowest during 

 the day (period of rest). 



Hilden and Stenback found that by imposing an 



