Ventilation. 39 



cannot be done, unless the construction of 

 the ship is favourable, which is a subject 

 outside the scope of the present remarks. 

 Respecting very free ventilation, I can state 

 that horses I have taken to Revel, via the 

 North Sea and Baltic during winter, suffered 

 no ill consequences from a ten days' sojourn 

 on an exposed deck with their heads 

 uncovered, while the thermometer at times 

 went several degrees below zero Fahrenheit. 

 Although the principles of ventilation are 

 the same on board ship as on land, the 

 details necessary for carrying them out, vary 

 to some extent, especially as regards the 

 establishment of inlets and outlets for air. 

 As a rule we may assume that the atmo- 

 sphere inside a ship is warmer than that 

 outside her, and consequently the tendency 



