100 Mr. H. Hamell on a New Anemometer. 



information relative to this subject given us by Barrow is, that 

 the Grenadier Grosbeaks are gregarious, and build their 

 nests in large societies. (Travels into the Interior of Southern 

 Africa, vol. i. p. 243). It may be safely inferred, however, 

 from what has already been stated with regard to the instinc- 

 tive propensities manifested by this species when in confine- 

 ment, that it is, strictly speaking, a Weaver Bird ; and this 

 opinion being supported by the general character of its ex- 

 ternal structure also, I have no hesitation in removing it from 

 among the heterogeneous forms with which it is associated in 

 the Linnnean genus Loxia, into a more appropriate situation, 

 namely, the genus Ploceus of M. Cuvier, still retaining its 

 original specific appellation. 



That the true place of a bird in the system of nature may 

 sometimes be ascertained by an attentive observation of its 

 manners in a state of captivity, I have attempted to show in 

 the case o^ Ploceus Oryx just detailed, and I trust with suffi* 

 cient success to induce those persons whose opportunities of 

 pursuing similar investigations are superior to my own, to 

 exert themselves in promoting the elucidation of this import- 

 ant branch of ornithology. 



XIV.' On a New Anemometer. By Hugh Hamell*. 



To the Editors of the Philosophical Magazine and Annals. 

 Gentlemen, 

 IVTR. STEVENSON in his account of the erection of the 

 -'-'-*- Bell Rock Light-house observes, " We cannot enough 

 regret the want of an efficient anemometer or instrument tor 

 measuring the force of the wind ; indeed we hardly know 

 any desideratum of more universal interest." It does not ap- 

 pear that this is yet supplied : and when we consider the many 

 very eminent men who have directed their attention to this 

 subject, and find nevertheless that they have not succeeded 

 in producing an instrument at once ready, accurate, and sen- 

 sible, it must be concluded that considerable difficulty lies in 

 the way. And though I will not presume to say that I have 

 completely ovei'come it, yet it appears to me that the instru- 

 ment which I now propose possesses advantages over any 

 other anemometer that I have seen or read of. 



Before describing the instrument, I wish to observe that 

 all the anemometers I am acquainted with are founded on one 

 or other of these two principles: the deflection of a pendu- 

 lous weight, or of a falling body, from the perpendicular ; or 

 the difference in elevation between the two columns of fluid 

 • Communicated by the Author. 



