24 THE ARCHITECTURE OF BIRDS. 



their watery way ; or the buoy that warns them of 

 the sunken rocks below, as this harmless wanderer, 

 whose manner informs them of the approach of the 

 storm, and thereby enables them to prepare for it." 

 The petrels are nocturnal birds. When, therefore, 

 they are seen flying about and feeding by day, the 

 fact appears to indicate that they have been driven 

 from their usual quarters by a storm ; and hence, 

 perhaps, arose the association of the bird with the 

 tempest. Though the petrels venture to wing their 

 way over the wide ocean as fearlessly as our swal- 

 lows do over a millpond, they are not, therefore, 

 the less sensible to danger ; and, as if feelingly aware 

 of their own weakness, they make all haste to the 

 nearest shelter. When they cannot then find an 

 island or a rock to shield them from the blast, they 

 fly towards the first ship they can descry, crowd into 

 her wake, and even close under the stern, heedless, 

 it would appear, of the rushing surge, so that they 

 can keep the vessel between them and the unbro- 

 ken sweep of the wind. It is not to be wondered at, 

 in such cases, that their low wailing note of weet, 

 weet, should add something supernatural to the roar 

 of the waves and whistling of the wind, and infuse 

 an ominous dread into minds prone to superstition. 

 The popular opinion among sailors, that the pe- 

 trels carry their eggs under their wings in order to 

 hatch them, is no less unfounded than the fancy of 

 their causing storms ; it is, indeed, physically impos- 

 sible. On the contrary, the petrels have been ascer- 

 tained to breed on rocky shores, in numerous com- 

 munities, like the bank-swallow, making their nests 

 in the holes and cavities of the rocks above the sea, 

 returning to feed their young only during the night, 

 wir.h the superabundant oily food from their stom- 

 achs. The quantity of this oily matter is so con- 

 siderable, that, in the Faro Isles, they use petrels 

 for candles, with no other preparation than drawing 

 a wick through the body of the birds from the mouth 



