49S THE PHILOSOPHY 



Their approach is recognifed by particular figns, fuch as the appear- 

 ance of certain fifhes, the vaft number of birds, as gannets or 

 folan geefe, which follow the fhoal to prey upon the herrings. But, 

 when the main body arrives, its breadth and depth are fo great as to 

 change the appearance of the ocean itfelf. The fhoal is generally 

 divided into columns of five or fix miles in length, and three or four 

 in breadth. Their progreffive motion creates a kind of rippling or 

 fmall undulations in the water. They fometimes fink and difappear 

 for ten or fifteen minutes, and then rife again toward the furface» 

 When the fun fliines, a vaiiety of fplendid and beautiful colours are 

 reflected from their bodies. In their progrefs fouthward, the firft 

 interruption they meet with is from the Shetland iflands. Here the 

 flioal divides into two branches. One branch fkirts the eaftern, and 

 the other the weftern fliores of Great Britain, and fill every bay and 

 creek with their numbers. Thcfe which proceed to the weft from 

 Shetland, after vificing the Hebrides, where the great fifhery is car- 

 ried on, move on till they are again interrupted by the north of Ire- 

 land, which obliges them to divide a fecond time. One divifioa 

 takes to the weft, where they are fcarcely perceived, being foon loft 

 in the immenfity of the Atlantic Ocean. The other divifion goes 

 into the Irifh Sea, and affords nourifhment to many thoufands of 

 the human race. The chief obje£l of herrings migrating fouthward 

 is to depofit their fpawn in warmer and more fhallow feas than thofe 

 of the Frigid Zone. This inftinft feems not to be prompted by a 

 fcarcity of food ; for, when they arrive upon our roafts, they are 

 fat and in fine condition ; but, when returning to the ocean, they 

 are weak and emaciated. They continue in perfedion from the end 

 of June to the beginning of winter, when they begin to depofit their 

 fpawn. The great ftalions of the herring fifheries are off the Shet- 

 land and the weftern iflands, and along the coaft of Norfolk. 



Befide 



