1839.] Distribution of the Vulturidce, Falconidce, fy Strigidce. 327 



of tropical countries ; for in very few instances do we find birds of 

 tropical countries extending their migrations to temperate countries, — a 

 statement which is applicable to more than a third of the birds of 

 Europe. But although we find these European birds inhabiting re- 

 gions within the tropics, yet we in general find them in those places 

 whose mean annual temperature is little above that of Europe, caused 

 either by the position or form of the country. To this rule however 

 we have several exceptions, as in the Sturnus vulgaris, Pastor roseus, 

 Oriolus galbula, which inhabit both tropical and temperate regions, 

 although probably more abundant, at least the last two mentioned, in 

 the former. It may also be noticed as a curious fact, the reason for 

 which is yet unexplained, viz. that the European species which are 

 found in tropical countries are in general smaller, although identical 

 in every other character with the same bird found in Europe ; in other 

 cases we find them not only smaller, but at the same time undergoing 

 slight modifications, which, however, are permanent, and therefore 

 entitling us to consider them as new species and the representatives, 

 in the particular regions in which they are found, of the European. Such 

 is the case with regard to the Nut-hatch, Blackbird, Goldfinch, Siskin, 

 Nut-cracker, Field-fare, Music Thrush, &c. all of which are found in 

 India. ( To be continued. ) 



Art. VIII. — On the use of Wells, 8$c. in foundations ; as practised 

 by the natives of the northern Doab. By Captain Cautley, Su- 

 perintendent of the Doab Canal. 



Piles and caissons being the usual means adopted for foundations 

 in Europe, where the soil and substrata are insufficient, I will ven- 

 ture a few remarks on the sj'stem adopted in northern India* for the 

 same purpose, especially in the application of hollow cylinders, or wells 

 of masonry. The plan of undersinking wells does not appear to be 

 totally unknown, although it is not practised in England ; in fact the 

 only approach to the method upon which I am now about to occupy 

 the pages of this Journal, is exhibited in the works at the Thames 

 Tunnel, at the descent to which Brunei has sunk masonry cylinders 

 " fifty feet in diameter, strongly clamped with iron, &c" the process of 

 effecting which I have no means of describing. Our Upper Indian 

 system, however, is so admirably adapted to the purposes for which it is 

 intended, and so much superior to pileing (caissons I put out of the ques- 



* The undersinking of wells, and their use in foundations, is not confined to the 

 northern Doab; it is practised in Bengal and other parts of India. 



