832 



SCIENCE. 



[N. S. Vol. XI. No. 282. 



- HIGHHOLB COURTSHIP AGAIN. 



To THE Editor of Science : On one of the 

 last days of April I noticed a pair of higliholes 

 on the turf about forty feet away. One would 

 drill the turf vigorously a few times, and then 

 nod the beak repeatedly with a sidewise motion 

 to the other — presumably the female, and this 

 one took no part in the turf-drilling. While 

 nothing passed from beak to beak, yet the 

 antic play rather confirmed my somewhat jest- 

 ing suggestion (Science, N. S., 1897, 921) that 

 it is a feeding pantomine, the female, like a 

 young bird, being receptive of the feeding atten- 

 tions of the mate. A thorough studj' of this 

 interesting bird through a telescope or powerful 

 glass ought to reward the observer. 



Hiram M. Stanley. 



Lake Forest, III., 

 May 7, 1900. 



A correction. 

 In a note printed on page 753 of Science 

 (May 11th), I inadvertently appear to advocate 

 the view that the current year belongs to the 

 twentieth century, which is not my opinion. 

 The sentence in question should have read " It 

 seems to me that that is reason enough why 

 we should- use '00 always to mean 1800, not 

 1900, even though the current year belongs to 

 the nineteenth century." 



E. L. Mark. 



the graphophone as an auxiliary astro- 

 nomical instrument, a suggestion. 



In order to insure as comprehensive and au- 

 thentic a graphic record of the appearance of 

 the solar corona, as deliberate and close obser- 

 vation and scrutiny limited to the few minutes 

 of totality can well be expected to furnish, I 

 beg leave to suggest the employment of an or- 

 dinary graphophone for taking down the ob- 

 server's talk instead of a short-hand recorder. 



The graphophone if properly set agoing and 

 manipulated will easily record all the observer 

 might choose to say for about three or four min- 

 utes, and therefore would enable him to give 

 his undivided attention to the examination and 

 thorough study of the aspect of the phenomenon , 

 without even the risk of being disturbed or in- 

 terrupted at the critical moments by questions 



etc. Nothing, it would seem, could possibly de- 

 feat securing by this means a complete and au- 

 thentic record of all an observer might feel 

 prompted to utter or note, except, perhaps in 

 the case the splendor of the corona should ren- 

 der him temporarily speechless. For verifica- 

 tion, if deemed necessary, employ a second 

 graphophone. The time of occurrence of any 

 unexpected event can be noted and recorded 

 upon the rotating barrel in several ways. 



A trustworthy and comprehensive graphic 

 account of the physical aspect of the corona 

 and chromosphere, would be valuable I should 

 think, in so far as it would supplement the 

 colorless work of the camera. 



W. E. 



NOTES ON PHYSICS. 



THE BLUE HILL KITE OBSERVATIONS. 



Me. H. H. Clayton, in an interesting letter 

 to Nature, April 26th, points out the bearing of 

 recent observations of temperature and wind 

 velocities at high altitudes upon the theories 

 of cyclonic movements of the atmosphere. 

 Four types of instability of the atmosphere are 

 now recognized : (1) Instability due to heating 

 of the lower strata of the atmosphere (vertical 

 temperature gradient). (2) Instability due to 

 the thrusting of large masses of warm air into 

 cool regions or of large masses of cold air into 

 warm regions, for example, a long continued 

 southerly wind carries a mass of warm air 

 northward into a region in which the surround- 

 ing air is cool (horizontal temperature gradient). 

 (3) Instability due to accumulation of water va- 

 por in the lower strata of the air. Such air 

 precipitates its moisture more and more as it 

 rises, is warmed by this precipitation and 

 rushes upwards with increasing violence. (4) 

 Instability of air streams which have passed be- 

 yond the region in which they are more or less 

 of the nature of permanent states of motion. 

 Thus the trade and antitrade winds in certain 

 regions show the characteristics of what are 

 called in hydrodynamics permanent states of mo- 

 tion and when they pass beyond these regions 

 they become dynamically unstable and break up. 



Each of these various types of atmospheric 

 instability has been put forth as the principal 

 cause of cyclonic motion by diflTerent writers 



