DESCRIPTION OF THE EXPEDITION. 31 
escape observation. And, finally, the latitude, longitude, and variation had to be 
accurately observed. All this, of course, had to be carried out upon or inside the reefs, 
but later on there were sections of soundings to be run outside so as to put in the 100- 
fathom line accurately. The resulting chart (fig. 10), on the scale of 6 inches to the mile, is 
wonderfully accurate, and is the largest chart of any atoll yet made. Charts on a lesser 
scale are almost too small to enable anyone to ascertain by accurate comparison the 
changes in the progress of atolls within any reasonable period of time, and we have no 
hesitation in declaring that the preparation of this chart is a work of the highest scientific 
Fig. 11. 
View from Takamaka over the Lagoon of Salomon Atoll, showing 
H.MLS. Sealark and [le Anglaise in the distance. 
importance. Commander Somerville and his officers have denoted an atoll for all time, 
so that by a re-survey at any future date its changes in progress may be ascertained and 
many points in the interaction of land and sea, and in the formation and growth of coral- 
reefs, may be accurately estimated. Their chart may not be of much economic value, since 
few ships visit the Salomons, but it will be of great importance to a knowledge of coral- 
reefs, such as will enable an estimate to be made of their probable growth and potential 
dangers to navigation in other places. 
The Salomon Atoll consists of eleven islands on a surface-reef, which surrounds the 
