140 Progress in Mechanics. [January, 



purposes of war. In the early campaigns of the French Republic a company 

 of ballooners was organised under a young doctor named Coutelle, which per- 

 formed good service ; and again, in the late civil war in America, they were 

 employed as aerial posts of military observation. At the present time a 

 balloon captif floats over Montmatre as a post of observation, and a regular 

 system of balloons has been established for postal purposes. At first letters 

 were sent off in passenger balloons, one of which consisted of three balloons 

 united together, and carrying 2 cwts. of letters. Another mode is now in 

 operation, and postal cards are sent off sometimes in free balloons. The 

 Brothers Godard have an atelier for the construction of balloons at the Orleans 

 Railway Station, whence several have already been made and sent off; these 

 balloons contain 2045 cubic metres ; but it is said that they are about to 

 construct a gigantic aerostat- to carry from twelve to fifteen passengers. 



M. Dupuy de Lome, formerly Chief Constructor of the French Navy, has 

 taken up the subject of aerial navigation. He posposes to form a balloon in 

 the shape of an elongated egg, the main axis to be horizontal and 130 feet 

 long, the transverse diameter 46 feet, and the total volume 3860 cubic metres. 

 The car is to be ovoid in form, and fitted with two spars or bowsprits, the 

 extremities of which will be 100 feet apart. The car is to be attached to the 

 balloon by means of shrouds fixed to these two spars, and to be suspended 

 about 50 feet below the balloon. A small triangular sail at one end of the car 

 is to perform the function of a rudder. The gas to be employed is the 

 ordinary carburetted hydrogen, and the ascensional force will be equal to 

 nearly three tons. The Government of Paris has voted a sum of 40,000 francs 

 to enable M. Dupuy de Lome to carry out his proposed plan of navigable 

 balloons. He proposes to work them by manual power. Another inventor is 

 engaged in the construction of an aerostat to be worked with steam or other 

 power. The Academy of Sciences of Paris has expressed a very decided 

 opinion against aerostats heavier than the air, moved by steam or other power ; 

 but it has given some countenance to a proposition by a M. Sorel, who uses a 

 sail as a rudder, and a screw simply to produce a difference between the 

 velocity of the machine and that of the wind. 



Loss of the " Captain" — The foundering of H.M.S. Captain, off Cape Finis- 

 terre, early on the morning of the 7th September last, has revived the question 

 of broadside versus turret ships. This ill-fated vessel, it appears, was con- 

 structed in direct opposition to the expressed opinions of Mr. E. J. Reed, the 

 late Chief Constructor of the Navy, who has always been opposed to vessels 

 having a low free-board. The Captain was originally to have had a free-board of 

 8 feet, but, owing to some alterations in her construction, possessed a considerably 

 increased immersion, the danger of which was publicly pointed out by Mr. Reed 

 in his letters to the " Times" about the period of her sailing on her last voyage. 

 The naval court-martial, before which the few survivors of the vessel were 

 arraigned, found in their verdict that the Captain was capsized " by pressure of 

 sail, assisted by the heave of the sea, and that the sail carried at the time of 

 her loss (regard being had to the force of the wind and the state of the sea) was 

 insufficient to have endangered a ship endued with a proper amount of 

 stability." They further remarked that the Captain was built in opposition to 

 the views and opinions of the controller and his department, and that the evi- 

 dence all tends to show that they generally disapproved of her construction. It 

 further appearing in evidence that, before the Captain was received from her 

 contractors, a grave departure from her original design had been committed, 

 whereby her draught of water was increased about two feet, and her free-board 

 was diminished to a corresponding extent, and that her stability proved to be 

 dangerously small, accompanied with an area of sail, under these circumstances, 

 excessive." This loss cannot fail to have the effect of, for a time, bringing into 

 disrepute a most valuable class of war vessel, and it is to be feared that this 

 calamity will prejudice the minds of Englishmen against turret ships long after 

 the real cause of its occurrence has been forgotten. 



The Solar Engine. — Captain John Ericsson, the well-known American 

 engineer, has recently been engaged in the construction of an engine to be 

 driven by means of solar heat, concentrated by the means of certain mechanism 



