60 ANNUAL OF SCIENTIFIC DISCOVERY. 



ture of the between-decks is higher than in vessels of any other class, 

 that in hot weather the iron walls suck up heat with the avidity of a 

 salamander, and that it is far from improbable that the practicability 

 of keeping the " bilges" sweet has been forgotten in the progress of 

 building (as in the case of the Warrior), we may also reasonably 

 infer that the principal conditions which concur in increasing the 

 foulness of the between-decks in wooden are also found in a higher 

 degree in armor-plated vessels. Hence we are led to the ultimate 

 conclusion that these latter ships promise to be much more destruc- 

 tive to their crews than any enemy ; at any rate, to estimate the 

 power of destruction by their offensive capabilities alone is a delu- 

 sion. 



The truth is, that, until the subject of ventilation enters as s} T stern- 

 atically into the scientific estimate of the construction of a ship as 

 speed and fighting qualities, the problem of ventilation will never be 

 rightly solved, the needless waste of life which now exists in our navy 

 in peace as well as war put an end to, and the chances of a catastro- 

 phe amongst the crew of our ironsides by the ravages of fever dimin- 

 ished. What would be the fate of the sailors of the Warrior or 

 Defence if typhus or yellow fever broke out on board ? to say 

 nothing of the chances of both officers and men being ignominiously 

 suffocated in their iron-cased domicil, under the blazing sun of the 

 torrid zone, after the fashion of certain doughty knights of old. 



French Results. Of the results and inferences arrived at by the 

 French authorities touching the construction and armament of iron- 

 clad vessels, the world knows but little beyond what has been neces- 

 sarily disclosed to the observer. It is believed, however, that they 

 have no faith in the Armstrong gun, or in any breech-loading gun 

 whatever ; and, also, that they reject the plan, followed to some extent 

 in England, of plating iron upon iron, but plate iron upon wood. 



The following is the reported strength of the French iron-clad 

 navy : Ten iron-cased floating batteries constructed during the Cri- 

 mean war ; two floating batteries of fourteen guns each, which have a 

 speed of six and one-half knots per hour, and are covered with four- 

 and-one-half-inch iron plates ; four iron-cased frigates afloat, namely, 

 the La Gloire, Normandie, Invincible, and Couronne, each of which has 

 engines of nine hundred horse-power, and a plating of four-and-three- 

 fourths-inch plates ; two armor-clad rams, which have engines of one 

 thousand horse-power ; from ten to fifteen large iron-cased frigates of 

 the La Gloire class on the stocks ; and about the same number of 

 armor-clad batteries in preparation, which are mainly intended for 

 harbor defences. 



A recent writer in the London Times, who professes to be posted, 

 states that " it is extremely doubtful whether any naval guns at pres- 

 ent introduced into the armament of iron ships could inflict any 

 serious damage on the French frigates La Gloire and the Normandie; 

 and it is certain that the French have introduced a gun which will 

 throw a flat-headed shot through four-aud-one-half-inch plates with 

 a thick timber backing. The armament of the Gloire itself consists 

 of guns (called jyieces -de 30) which, with a charge of rather more 

 than fifteen pounds of powder, throw a ninety-pound shot through 

 twelve centimetres of iron plating at forty metres. But the French 



