328 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Sixth. When the workman comes from the chamber of 

 compressed air, he should enter into an intermediate cham- 

 ber, in which change from compressed to normal air shoukl 

 take place gradually during the space of about fifteen min- 

 utes. 



Seventh. The workman should, before passing from the 

 warm air of the chamber to the cold air, exchange his damp 

 clothes for those that are warm and dry. Technisclie Blat- 

 ter Vierteljahrschrift^ Bohemian JPolytech. Assoc, 1872, 32. 



FOOD OF THE BASKIXG SHAKK. 



Among the sharks inhabiting the northern seas, the Bask- 

 ing Shark (Selache maximi(s) occupies a very prominent place 

 on account of its enormous size individual specimens of 

 thirty to forty feet in length being not at all uncommon, 

 and exceeding in size any others of the group with which we 

 are familiar. It is said that sharks over sixty feet in length 

 have been found in the vicinity of the Seychelles and Philip- 

 pine Islands ; but nothing approaching that size is seen in 

 the basking shark of Europe and North America. 



With all its great bulk, the animal is provided with ex- 

 tremely minute teeth, so small, indeed, as to indicate a differ- 

 ent mode of life from that of the ordinary species. Its inof- 

 fensive nature is well known, as it is constantly hunted for 

 the oil of its liver; and it is never found to make any resist- 

 ance when disturbed, much less to attack man sj^ontane- 

 ously. 



Naturalists have long since observed a peculiar sieve-like 

 apparatus in the mouth, resembling a comb with very long 

 teeth, the precise function of which has not been well estab- 

 lished. 



Dr. J. S. Steenstrup, the eminent Danish naturalist, however, 

 has lately come to the conclusion that the animal feeds upon 

 minute crustaceans and other objects; and the general re- 

 sults of his inquiry are ably summed up by The Academy as 

 follows: 1. The basking shark has the interior of its mouth 

 furnished with a fringe or branchial mesh, which presents 

 the appearance of small rays like whalebone, about five or six 

 inches in length. These meshes are situated along the enor- 

 mous branchial slits, and serve as a strainer to collect par- 

 ticles of food. 2. This branchial frincre is of the same nature 



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