396 THE GANNET 



It is difficult to name the maximum height of a Gannet's 

 plunge, but the most reliable observations were those 

 made by Mr. W. E. Clarke, when spending a month for 

 migration study on Eddystone Lighthouse.* Knowing the 

 level of the lighthouse gallery, he was able to determine 

 approximately the height of many plunges, and in his 

 opinion none, out of many thousand, exceeded one hundred 

 and forty feet. Norman Heathcote thought some reached 

 one hundred and fifty feet.f The average drop, however, 

 would be much less than that. The drop of a Common Tern 

 into the sea is only twenty feet, and is light compared to 

 the Gannet's weighty fall, yet in form they are not unlike ; 

 but there is a great difference of structure and an enormous 

 difference in bulk. Nor can the Gannet be compared to the 

 Kingfisher — another plunger with a heavy body, but with 

 no subcutaneous cells to protect it. 



The first point in a Gannet's mechanism to be 

 noticed is the setting on of the wings, which are exactly 

 adapted for assuming the perpendicular when in the act of 

 falling in the air, for it will be seen that they are attached 

 nearer to the centre of gravity than in most birds. When 

 a Gannet reverses in the air, it falls of its own weight, and 

 nothing is needed but a motion of the elbow, at the junction 



* " Ibis," 1902, p. 264. 

 ■j- "St. Kilda," p. 160. 



