56 THE ACCLIMATISATION 



the other side of the globe. The principle 

 involved in carrying ova such a distance is 

 that of retarding the natural process of 

 hatching. Ice, then, is the agent employed. 

 But how is ice to be preserved on a journey, 

 the greater part of which is performed in a 

 temperature very much above, and not 

 often much below, our summer heat ? A 

 description of the ice-house on board the 

 Oberon, which will take out the present 

 consignment of ova to Otago, will best 

 answer that question. A space, whose 

 internal dimensions are rather more than 

 13 ft. by 9 ft. by 8 ft., is enclosed by bulk- 

 heads a httle abaft the foremast, and situated 

 upon the hold of the vessel below the water 

 Hne. This forms the ice-house, which is 

 surrounded by a " skin " of powdered char- 

 coal about one foot thick, as a non-con- 

 ductor, and lined throughout with sheet 

 lead. On the floor of the ice-house is a 

 wooden grating to carry off all water from 

 the melting ice, which, after passing through 

 the grating, finds its way to the bilge of 

 the vessel through small scuppers at each 



