92 THE SPEED OF THE PIGEON-POST 



beach. The natives catch the young birds, tie them 

 by the leg, and feed them till they become tame. 

 Then they let them loose, when they regularly go out 

 to sea to obtain food, and come back to roost. Ad- 

 vantage was taken of this by some of the missionaries 

 to establish a ' pigeon-post,' conducted by frigate-birds, 

 between the islands, and Mr. Whitmee himself saw 

 more than one letter arrive in a quill attached to the 

 wing of a frigate-bird. Here there is a perfect oppor- 

 tunity, ready made, for determining the speed of one 

 of the finest fliers among the whole nation of birds. 

 It is not likely that the natives of these islands, or, 

 rather, islets, north of Fiji and east of Samoa, have 

 ceased to tame the birds, and the missionaries now on 

 the islands might renew the experiment of the past, 

 and make a trustworthy record. A very ingenious 

 means of observing the speed of flight was suggested by 

 MM. Liais and Mouillard. This was to fly a bird 

 across some open area of sand, and measure the time at 

 which the shadow crossed lines marked upon it. But 

 the photographic gun of M. Marey gives excellent 

 results. If the bird is crossing the spectator, it will 

 show on a spinning disc images at the rate of ten in a 

 second. When the space between the images is 

 measured, and compared with the length of the bird's 

 body on the plate, the speed at which it is travelling 

 can be calculated at once. Observations made from 



