DAVY JOXES'S LOCKEK. 79 



On the Bahama banks and in the Gulf of Mexico the sponges grow in water of small 

 depth. The fishermen Spanish, American, and English sink a long mast or perch into the 

 water moored near the boat, down which they drop upon the sponges ; by this means they are 

 easily gathered. 



The fine, soft Syrian sponge is distinguished by its lightness, its fine flaxen colour, its 

 form, which is that of a cup, its surface convex, voluted, pierced by innumerable small orifices, 

 the concave part of which presents canals of much greater diameter, which are prolonged to the 

 exterior surface in such a manner that the summit is nearly always pierced throughout in many 

 places. This sponge is sometimes blanched by the aid of caustic alkalies ; but this preparation 

 not only helps to destroy its texture, but also changes its colour. This sponge is specially 

 employed for the toilet, and its price is high. Specimens which are round-shaped, large, and 

 soft, sometimes produce very large prices. There are many other varieties known to the 

 commercial world. 



CHAPTER VII. 



DAVY JONES'S LOCKER, AND THOSE WHO DIVE INTO IT. 



Scientific Diving -General Principles William Phipps and the Treasure Ship Founder of the House of Mulgrave 

 Halley's Wooden Diving-bell and Air Barrels Smeaton's Improvements Spalding's Death Operations at Plymouth 

 Breakwater The Diver's Life" Lower away ! "The Diving-Belle and her Letter from Below Operations at the 

 Bottom Brunei and the Thames Tunnel The Diving Dress- Suffocation Remarkable Case of Salvage The "Sub- 

 marine Hydrostat" John Gann of Whitstable Dollar Row Various Anecdotes Combat at the Bottom of the 

 Sea A Mermaid Story Run down by the Queen of Scotland. 



THE art of unassisted diving having been considered, the reader's attention is invited to 

 divers and diving aided by scientific appliances. But for these developments, how 

 could one hope to recover anything large or valuable that had once disappeared beneath 

 the waves? How properly build gigantic breakwaters, piers, and bridges, or examine 

 and clear choked ports and channels ? * Some of the grandest achievements of modern 

 practical science would have been impossible without their aid. 



Every reader understands the general principle involved in the construction of the 

 diving-bell. Invert a tumbler in a deep vessel of water, and the liquid will only ascend 

 to a certain height inside, however far down you place the glass. Insert a tube in a 

 hole drilled in your tumbler, and blow downwards, and the water recedes still lower. This 

 is what happens when the air is pumped down into the modern diving-bell. In 

 descending in a diving-bell and remaining under water you will feel a slight incon- 

 venience in breathing, and perhaps a tingling in the ears; this comes, not from scarcity 

 of air, but from the fact that the atmosphere of the interior of the bell is really 

 denser than it is outside; the air, forced downwards by the powerful air-pump, is pressed 

 upwards by the water. Readers may remember that Robert Fulton and his friends 



* The bulk of this chapter is derived from the following works: "The Conquest of the Sea," Siebej 

 " English Seamen and Divers," M. Esquiros ; an Article in " The Shipwrecked Mariner," Vol. XXII. ; &c. 



