180 LECTURES. 



holes of Calcutta" as well as the land. In some cases almost every 

 individual confined under deck, in a storm, had been literally suffo- 

 cated in consequence of the want of fresh air. Even a very few years 

 ago a case of this kind had occurred in the Irish channel. Still more 

 recently hundreds of Chinese had perished on board ship from the 

 same cause. During the late Crimean war, the suffering and death on 

 shipboard, during a storm in the Black Sea, had been extreme. In 

 one of the most crowded vessels, where defective ventilation added its 

 horrors to disease, nearly a hundred perished in a single night. How 

 often was it forgotten that a very small cause would put out the fee- 

 ble flame of life, when it had to struggle at the same time against 

 disease and against a vitiated atmosphere, poisoning the very foun- 

 tain at which it should be renewed at the rate of twelve hundred 

 respirations every hour. If it had been right in him to advocate the 

 cause of general education in the elements of science in speaking of 

 other cases where ventilation was necessary, it was still more essential 

 that it should not be forgotten as a means of promoting the purity 

 of the air of ships. 



On examining the condition of ships-of-war, packets and merchant 

 vessels, when his attention was first specially directed to this depart- 

 ment, he had not met with a single case in which any arrangements had 

 been made beyond the windsail, and occasionally a few copper or other 

 tubes, acting locally for the supply or discharge of air, and not gene- 

 rally on the whole ship. The effect of these was entirely dependent 

 on "the slate of the wind. There was no ventilating power that 

 could be put in operation in calm weather, sufficient to meet the 

 contingency of a storm when all side ports and scuttles were closed, 

 and even the very hatches battened down to prevent the ingress of 

 water from the deck. In experiments which he had made on board 

 the Benbow, a seventy-two gun ship, by the kindness of Admiral 

 Houston Stewart, he had used a fanner that sustained a plenum cur- 

 rent in a tube made of canvass about four or five feet in diameter. 

 He had afterwards seen a small fanner introduced by Captain War- 

 rington, who had been strongly imjjressed in a voyage from India 

 with the necessity of the ventilation of ships. But whether fanners^ 

 screws, pumps, or any other variety of mechanical power was used 

 for this purpose, a system of tubes or ventilating channels was 

 absolutely essential to admit of a satisfactory effect being insured, 

 particularly on those occasions when ventilation was most imperiously 

 demanded. A ventilating power worked by heat alone was not so 

 generally available on board ship as other means ; still, however, it 

 could be used with advantage in many cases when judiciously applied, 

 and the cooking stove could often be rendered useful for this purpose 

 by intelligent officers. In steamboats, the machinery and the tires 

 for the production of steam gave twofold facilities for ventilation. 

 It was inexcusable, therefore, that they should not be more systemati- 

 cally ventilated than they generally were. Any amount of appro- 

 priation, almost, could often be secured for the most superb cabin 

 decorations, while a comparatively trifling sum was as often denied 

 for the means of giving the pure breath of life. 



A diagram was then shown illustrative of the plans executed by 



