THE MUSIC OF THE BIRDS. 255 



* 

 At first thought, it was some bird that had practiced under a 



cuckoo master. It was an anxious moment, but presently all was 



settled : 



fe$ | _ 1 1 r = 



^ 



Cuck - 00, cuek - oo, 



1 



cuck - 00. cuck - 00. 



The instant I heard " cuckoo," more especially the second one, 

 giving the interval of a fourth, I experienced a thrill of satis- 

 faction such as no similar discovery had afforded. Other ears, 

 sharper than mine, had heard all, unknown to me, and there was 

 great rejoicing ; the cuckoo was learning to sing. 



Yellow-billed Cuckoo. The yellow-billed cuckoo, though 

 he tries hard to make a showing of vocal talent, succeeds only 

 in producing a slovenly, guttural blubbering, with barely tone 

 enough to give positive pitch. The beginning of this effort is a 

 sepulchral and somewhat protracted sound, which bursts into 

 several rapid, boisterous bubbles, followed by others softer and 

 slower, farther and farther apart : 



f ^ rit. e dim 



-bt 9 9 9r 



y F- 1 1 1 p. h 



9 9 9 9 9 9V 9 9 9 9 



Wau - olp, olp, olp, olp, olp, olp, olp, olp, olp, olp, olp. 



The yellow-breasted chat exhibits the same rhythmic pecul- 

 iarity in his chattings, and so does the woodpecker, drumming 

 on a board or dry limb for the mere sound of it ; but in quality 

 nothing can be compared with this slopping performance, unless 

 it be that of the loose-mouthed hound lapping from a pan of milk. 



The cuckoos, graceful, beautiful birds, and ever rapt in solemn 

 reverie, are solitary voices, seldom heard more than one at a time. 



Observations carried on for nearly two years at the observatories of Berlin, 

 Potsdam, and Prague indicate the existence of a periodical oscillation in latitude. 

 The maximum occurs in summer, the minimum in winter, and the amount is 

 0' 25". The observations have been conducted with the greatest exactitude, and 

 the results of the three sets are concordant. M. Gaillot has communicated a similar 

 result from observations taken at Paris between 1856 and 1861. The variation 

 may be ascribed to a periodical displacement of the earth's axis, in which case, 

 while the amplitude of the phenomena will be the same at all stations, the times of 

 maxima and minima will vary with the longitude; or it may be an effect due to 

 refraction, in which case the periods will be the same at all the stations. 



