February 24, 1922] 



SCIENCE 



209 



source of sounds, under the headiiig, "Have 

 Birds an Acute Sense of Sound Location^" He 

 closes by saying that he would appreciate any 

 direct observational data touching upon this 

 subject. The following is an affirmative an- 

 swer to his question: 



On the morning of September 9, 1921. when 

 in camp near Kneeland post office, Humboldt 

 County, California, while I was seated amjng 

 some rather tall bushes, watching for sparrows, 

 a Sharp-shinned Hawk (Accipiter velox) flew 

 on to a lower limb, some thirty or forty feet 

 above the ground, of a dead fir tree about 

 seventy yards away, alighting with its back to- 

 ward me. While the bird was visible to me 

 through the small openings among the branches 

 of the bushes I must have been absolutely 

 hidden from its view. 



Just to see what the result would be I 

 squeaked in imitation of a wounded bird when, 

 to my great astonishment, the hawk wheeled as 

 if on a pivot with remarkable rapidity and 

 darted in a bee line over the tops of the bushes 

 straight in my direction. When it reached the 

 spot directly over my head, and not six feet 

 above me, it e^ddently was aware that it had 

 reached the center of the sound field for, not 

 seeing anything there to account for the sound, 

 it shot abruptly up into the air and lit on a 

 limb of another dead fir so close to me that I 

 shot it with my 32 caliber ausiliary barrel 

 with a small charge of No. 12 shot. 



The most curious part of this incident is that 

 the hawk did not stop to listen and analyze 

 or locate the sound, as might a jay for instance, 

 but with the first squeak it turned quick as a 

 flash, and darted with arrowlike speed for the 

 spot from which the sound emanated ; that is to 

 say on the exact line (more correctly, vertical 

 plane) between its perch and the spot, as the 

 height of the bushes prevented it from aiming 

 its flight quite low enough. It seemed to me 

 that if my head had been high enough to be 

 aljove the bushes it would have struck me. 



This was the most remarkable exhibition of 

 instantaneous precision in locating sound, not 

 only as concerns direction but also as to rapid- 



1 Science, New Series, Vol. LIII, No. 1375, 

 May 6, ],921, p. 439. 



ity of impulse, that it has been my good for- 

 tune to witness. 



Joseph IIailliard 

 California Academy of Sciences, 

 San Francisco, California 



SCIENTIFIC BOOKS 



Deodat Dolomieu, membre de I'Institut Na- 

 tional (1750-1801) ; sa correspondance, sa 

 vie aventureuse, sa captivite, ses ceuvres. 

 Alfred Lacroix. Ouvrage publie par 

 I'Academie des Sciences avec le concours de 

 I'Institut (Fondations Debrousse et Gas) 

 Paris, Librarie Academique, Perrin et C''=, 

 1921, 2 vols, Ixxx, 255, and 322 pp., port., 

 8vo. With line iDortrait frontispiece. 



The latest work of Professor Alfred Lacroix 

 is a very important contribution to the history 

 of the scientific men of France in the eighteenth 

 century, perhaps all the more so that the name 

 of Dolomieu is not well known in foreign lands. 



The book has grown out of the researches 

 made by Professor Lacroix in preparing the 

 biographical sketch of Dolomieu which he read 

 before the Academic des Sciences on December 

 2, 1918, and which has already been reviewed in 

 Science. He found a number of Dolomieu's 

 letters in the library of the Museum d'Histoire 

 Naturelle, and traced out many others in for- 

 eign libraries and in private hands. The author 

 remarks that the chief value of those letters he 

 has selected for publication is that they include 

 a series, covering a period of some twenty years, 

 written by Dolomieu to a small number of par- 

 ticular friends, so that they enable the reader 

 to follow his life day by day in its more inti- 

 mate details. The earliest in date of these 

 letters were addressed by Dolomieu to his pat- 

 ron, Duke Alexander de la Rochefoucauld, 

 member of the Academic des Sciences and 

 colonel of the regiment "De la Sarre," who was 

 destined to be assassinated in 1792, almost in 

 Dolomieu's arms. 



An interesting group of 47 letters are those 

 written to the Sicilian naturalist Giseni; these 

 treat at length of the important investigations 

 of Dolomieu in the domain of volcanic forma- 

 tions. Other groups of letters are those sent to 



