enlarge into the plumed tops of cocoa-nut trees, and a line of green, interrupted at intervals, is traced along the water's surface. Approaching still nearer, the lake and its belt of verdure are spread out before the eye, and a scene of more interest can scarcely be imagined. The surf, beating loud and heavy along the margin of the reef, presents a strange contrast to the prospect beyond. There lie the white coral-beach, the massy foliage of the grove, and its embosomed lake with its tiny islets. The color of the lagoon-water is often blue as the ocean, although but 10 or 20 fathoms deep, yet shades of green and yellow are intermingled." In some instances there is a ship-channel through the reefs into the lagoon, in others only a shallow passage, in others none at all.
Fig. 14.
Coral Island, or Atoll.
By a series of soundings, we have some idea of the depth of water near the ocean-side of many of the great reefs.
Seven miles from Clermont Tonnerre, of the Panmotus group, bottom was not found at 6,870 feet. From another point of the same island, only 1,500 yards from shore, the lead touched at 2,100 feet, then dropped off (probably from a projecting coral), and descended 3,600 feet without finding bottom. In another instance, about a cable's length from the island of Ahii (Peacock Island), in the same group, the lead struck at 900 feet, fell off and touched bottom at 1,800 feet. Off Whitsunday, 500 feet from the shore, no bottom was found at 1,500 feet. Deep soundings in the immediate vicinity of coral-islands is almost universal. Should these submerged islands of the Pacific be again elevated until their gigantic coral crowns should be lifted above the waves, an immense area of the Pacific would be converted again into an archipelago, not indeed of verdure-covered land as before, but of hills and mountains of coral-rock, bristling with crags, sublime with precipices and stupendous walls.
The great coral-bearing area of the Pacific is about 12,000,000 square miles in extent, nearly as large as the continent of Africa, or of Europe and North America combined. It extends from the southern side of the Hawaiian Islands to Pitcairn's Island to the southeast, thence 2,000 miles broad and 6,000 miles in length to the Pelew Islands, north of New
