1875 VENTILATION. 181 



With a greater cubic space per man in the ' Alert ' 

 than in any former Arctic discovery ship excepting 

 the ' North Star,' I hoped that with care the dampness 

 would be lessened. In this I was not disappointed, 

 but although every means in our power was taken to 

 reduce it to a minimum, it still existed to a consider- 

 able extent. 



The object in both ships was to increase the size 

 and height of the mess-deck as much as possible, by 

 building snow-houses with wooden roofs over each 

 hatchway ; also to enlarge the entrance porches at the 

 top of each communication hatchway. In the ' Alert ' 

 a snow-house was erected on the upper deck above 

 the galley hatch, fifteen feet long and nine broad ; this 

 acted admirably as a condenser, collecting the steam as 

 it rose from the boilers below. The porches on the 

 upper deck were doubled in size, forming rooms eight 

 feet square. The walls being composed of hard snow- 

 blocks and having ventilating holes in them, the tem- 

 perature of the descending air, by passing through 

 the warmed snow-chamber, was by this means raised 

 considerably before it reached the lower deck. 



The washing and drying room at the extreme end 

 of the lower deck was kept quite distinct from where 

 the men lived ; the forecastle above it being converted 

 into a snow-condensing chamber, the damp air from 

 the washing room below ascended into it and passed 

 out through a ventilating tube. 



In our endeavour to get rid of the rarefied air 

 from the ship several ' uptakes ' were introduced, but 

 only those above the hatchways answered the purpose 

 satisfactorily ; many of the rest, being more frequently 



