Submarine Appliances And Their Uses
Deep Sea Diving, &c., &c.

Fig. No. 84. Borellus’ The next illustration is worthy of special note inasmuch that the apparatus depicted Apparatus. _ J. 1 . r __ therein aims at the renewal of the air and the separation of the exhaled from the in- spiratory air. This apparatus was designed by Borellus, and the following description is taken from his work Motu Animaliumf' Rome, 1682 :— Make a vessel, or iron or tin hollow body, as shown in “ M—H,” 2 feet in diameter, which can be put over the head “A ” of a man like a helmet, so that the head is enclosed as in a chamber, and which fits accurately upon the shoulders, nape of the neck and chest, the metal neck being tied fast with cords, and. the man being dressed in a dress of buckskin; thus a man equipped in this way will be able to live tinder water for some hours, free and unimpeded, the air enclosed in the metal vessel “ M—H ” being, so to speak, renewed from time to time, as will be shown later on. You must make a curved metal tube “ J K L,” 3 feet long, to which at the central lowermost curve a leather sac is attached, and the tube must also have, from the outside, two orifices or nozzles “J—L,” which, within the hollow vessel, surround the head, in order that air can be inhaled through the anterior orifice “ J ”, and exhaled through the posterior orifice “ L.” By this device two advan- tages are afforded. Firstly, the air, which is in- haled from the tube, is rendered fresh and good again by the surrounding water (as also all the air contained in the whole vessel), by the long travel through the tube "JKL/' Secondly, the exhaled air, on inhaling through the narrow neck at the orifice of the tube “ J,” passes out, not through the nose, but through the mouth alone, as experience shows ; if then the ex- haled air is drawn by the inhalation into the long, follow that, through this passage and roundabout F curved tube, it must necessarily way, drops of moisture or vapour will adhere, and. trickle down inside the tube, and be collected in the leather sac, just as in a still; hence it comes that the air will go out through the orifice “ L,” which goes round the curve, and thus become not only fresh but also pure, clear and dry, and therefore the diver will not inhale the warm breath exhaled through month and nose, but he will receive and enjoy a quite different, fresh, pure air, and under these circumstances he can breathe quite comfortably for half an hour without danger. But as nevertheless no one could sustain life unless the air enclosed, in the vessel is renewed, it is highly necessary that the vessel “ 2 ” should have metal tubes “ N—O,’J with closed cock, so that in case of necessity, on coming to the surface, one can exhale through one pipe “ P—O ” and draw in fresh air through the other tube “ N,” and, after closing the cocks, redescend. Besides, the metal vessel or body put over the head must have, in front, as shown, “2—3,” a hole into which plate glass, fused on, is inserted, so that the diver may be able to see. Os O