194 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



triches in a state of domestication without too much trouble 

 and expense, the broods may be rendered of much pecuniary 

 value, since the plumes alone of the male birds will bring a 

 price so great as to yield a handsome return, and the remain-, 

 ing feathers of the body generally of both sexes can be turned 

 to economical account. How far ostriches can be utilized in 

 civilized countries as animals of draught and beasts of bur- 

 den, as they are said to be employed in Africa, remains to be 

 tried. 1 C, xxxi.,459. 



BREEDING OF OSTRICHES IN CAPTIVITY. 



The preceding article has reference to the subject of the 

 breeding of ostriches in captivity in Europe, and we are re- 

 minded that this is a practice of common occurrence in South 

 Africa, where large numbers are kept for the purpose of se- 

 curing successive crops of their feathers, and are inclosed in 

 areas of fifteen to twenty acres, encircled by low stone walls. 

 Their eggs are usually hatched artificially by being kept at 

 a temperature of about 100 degrees by the aid of an oil lamp. 

 The long white feathers of the wings of the male birds are 

 the most valuable, bringing from $150 to $200 a pound, eighty 

 feathers usually making up this weight. The feathers from 

 the wild birds are, however, considered more valuable than 

 those taken on the farms. 



marey's apparatus for recording the flight OF BIRDS. 



Much interest was excited by the account given a year or 

 two ago by Professor Marey of the phenomena of night in 

 birds and insects, as illustrated by apparatus devised by him, 

 which actually traced on paper the curve described by the 

 point of the wing in flying. The professor, during the dis- 

 turbances caused by the late war in France, was steadily oc- 

 cupied in continuing his researches, and presented to the 

 Academy of Sciences, some months since, a continuation of 

 his series of communications, in which he discusses the move- 

 ment which the action of the wing produces upon the body 

 of the bird itself. He shows that the progression of the bird 

 when flying, in consequence of the beating of its wings, takes 

 place along an undulating line, the sinuosities of which are 

 produced by the slight leaps of the animal. These move- 

 ments can in certain cases be appreciated by the eye, as when 



