PROTO-BATHYSPHERES 5 5 



were commonly known) might be a sufficient help against 

 this greatest difficulty. 



"As for the many advantages and conveniences of such 

 a contrivance, it is not easie to recite them. 



"i. 'Tis private; a man may thus go to any coast of 

 the world invisibly, without being discovered or prevented 

 in his journey. 



"2. 'Tis safe; from the uncertainty of Tides, and the 

 violence of Tempests, which doe never move the sea about 

 five or six paces deep; From Pirates and Robbers which 

 do so infest other voyages; From ice and great frosts which 

 doe so much endanger the passages towards the Poles. 



"3. It may be of very great advantage against a Navy 

 of enemies, who by this means may be undermined in the 

 water and blown up. 



"4. It may be of a special use for the relief of any place 

 that is besieged by water, to convey unto them invisible 

 supplies; and so likewise for the surprisal of any place that 

 is accessible by water. 



"5. It may be of unspeakable benefit for submarine ex^ 

 periments and discoveries: as, 



"The several proportions of swiftnesse betwixt the 

 ascent of a bladder, cork, or any other light substance in 

 comparison to the descent of stones or lead. The deep 

 caverns and subterraneous passages where the sea-water in 

 the course of its circulation doth vent it self into other 

 places and the like. The nature and kinds of fishes, the 

 severall arts of catching them, by alluring them with 



