88 THE SEA. 



obliged to use iron instead of brass or copper for bolts and arbours. Notwithstanding 

 these disadvantages, he engaged in a course of experiments with the machine, which 

 required no less courage than energy and perseverance. Of his proceedings he made a 

 report to the committee appointed by the French executive, from which report we learn 

 the following interesting facts: 



"On the 3rd July, 1801, he embarked with three companions on board his plunging- 

 boat in the harbour of Brest, and descended in it to the depth of five, ten, fifteen, and 

 so to twenty-five feet; but he did not attempt to go lower, because he found that his 

 imperfect machine would not bear the pressure of a greater depth. He remained below 

 the surface one hour. During this time they were in utter darkness. Afterwards, he 

 descended with candles ; but, finding a great disadvantage from their consumption of 

 vital air, he caused, previously to his next experiment, a small window of thick glass to 

 be made near the bow of his boat, and he again descended with her, on the 24th 

 July, 1801. He found that he received from his window, or rather aperture covered 

 with glass, for it was no more than an inch and a half in diameter, sufficient light to 

 enable him to count the minutes on his watch. Having satisfied himself that he could 

 have sufficient light when under water, that he could do without a supply of fresh air 

 for a considerable time, that he could descend to any depth, and rise to the surface 

 with facility, his next object was to try her movements as well on the surface as 

 beneath it. On the 26th July he weighed his anchor and hoisted his sails; his boat 

 had one mast, a mainsail, and a jib. There was only a light breeze, and, therefore, 

 she did not move on the surface at more than the rate of two miles an hour, but it 

 was found that she would tack and steer, and sail on a wind or before it, as well as 

 any common sailing-boat. He then struck her mast and sails; to do which, and 

 perfectly to prepare the boat for plunging, required about two minutes. Having 

 plunged to a certain depth, he placed two men at the engine, which was intended 

 to give her progressive motion, and one at the helm, while he, with a barometer before 

 him, governed the machine which kept her balanced between the upper and lower 

 waters. He found that with the exertion of one hand only, he could keep her at any 

 depth he pleased. The propelling engine was then put in motion, and he found, upon coming 

 to the surface, that he had made, in about seven minutes, a progress of four hundred meters, or 

 about five hundred yards. He then again plunged, turned her round while under water, and 

 returned to near the place he began to move from. He repeated his experiments several 

 days successively, until he became familiar with the operations of the machinery and the 

 movements of the boat. He found that she was as obedient to her helm under water 

 as any boat could be on the surface; and that the magnetic needle traversed as well in 

 the one situation as in the other. On the 7th August, Mr. Fulton again descended with a 

 store of atmospheric air compressed into a copper globe of a cubic foot capacity, into 

 which two hundred atmospheres were forced. Thus prepared, he descended with three 

 companions to the depth of about five feet. At the expiration of an hour and forty minutes, 

 he began to take small supplies of pure air from his reservoir, and did so, as he found 

 occasion, for four hours and twenty minutes. At the expiration of this time he came to the 

 surface, without having experienced any inconvenience from having been so long under water." 



