SOLAR ECLIPSE, MAY 0, 1883. 23 



"The emerged land beyond the beach in its last stage stands G to 10 feet ont of water. The 

 surface consists of coral sand, more or less discolored by vegetable or animal decomposition. Scat- 

 tered among the trees stand, still uncovered, many of the larger blocks of coral, with their usual 

 rough angular features and blackened surface. There is but little dejith of coral soil, although 

 the land may appear buried in the richest foliage. In fact, the soil is scarcely anything but coral 

 sand. It is seldom discolored beyond 4 or 5 inches, and but little of it to this extent. There 

 is no proper vegetable mold, but only a mixture of darker particles with the wliite grains of coral 

 sand. It is often rather a coral gravel, and below a foot or two it is usually cemented together 

 into a more or less compact coral sand-rock. 



" The shore of the lagoon is generally low and gently inclined, yet in the larger islands [as at 

 Caroline Island] there is usually a beach resembling that on the seaward side, though of less 

 extent. A platform of reef-rock, at the same elevation as the shore-platform, sometimes extends 

 out into the lagoon ; but it is more common to liud it a little submerged, and covered for the 

 most part with growing corals; and, in either case, the bank terminates outward in an abrupt 

 descent, of a few yards or fathoms, to a lower area of growing corals or to a bottom of sand. 

 Still more commonly we meet with a sandy bottom, gradually deepening from the shores, without 

 growing coral. These three varieties of condition are generally found in the same lagoon, char- 

 acterizing its diflerent parts. The lower area of growing corals slopes outward and ceases when 

 the depth is 10 to 12 fathoms or sooner. 



"There are usually currents flowing to leeward through the lagoon, and out, over, or 

 through the leeward reef, the waves with the rising tide dashing over the windward side, and 

 keeping up a large supply, which is greatly increased in times of storms ; and this action tends to 

 keep open a leeward channel for the passage of the water." 



The various illustrations scattered through this section (which are engraved from photographic 

 prints kindly furnished by the gentlemen of the English expedition) will make this description 

 more clear to those who have not aetually seen a coral atoll. They have been redrawn from the 

 prints by Mr. R. N. Brooke, of Washington, to whom our thanks are due for the care which he 

 brought to his difficult task. 



From Darwin's Journal the following extracf;s are taken : 



"The ring-formed reef of the lagoon island is surmounted in the greater part of its length by 

 linear islets. On entering the lagoon the scene was very curious and rather pretty. Its beauty, 

 however, entirely depended on the brilliancy of the surrounding colors. The shallow, clear and still 

 water of the lagoon, resting in its greater part on white sand, is, when illumined by a vertical sun, 

 of the most vivid green. This brilliant expanse, several miles in width, is on all sides divided, 

 either by a line of snow-white breakers from the dark heaving waters of the ocean, or from the 

 blue vault of heaven by the strips of land, crowned by the level tops of the cocoauut trees. As a 

 white cloud here and there affords a pleasing contrast with the azure sky, so in the lagoon, bands 

 of living coral darken the emerald-green water." 



"The next morning after anchoring I went on shore. The strip of dry land is only a few hun- 

 dred yards in width. On the lagoon side there is a white calcareous beach, the radiation from 

 which under this sultry climate was very oppressive; and on the outer coast, a solid broad plat of 

 coral rock served to break the violence of the open sea. Excepting near the lagoon, where there is 

 some sand, the land is entirely composed of rounded fragments of coral. In such a loose, dry, 

 stony soil, the climate of the intertropical regions alone could produce a vigorous vegetation. On 

 some of the smaller islets nothing could be more elegant than the manner in which the young an^ 



