TOPOGRAPHY. 15 
and others still beyond, which extend the line to longitude 136° W. 
There is little doubt that the whole should be included in one system 
or range. 
e. Atiu or Hervey Group.—South and west of Tahiti lie a number 
of small islands, the western of which have been called the Hervey 
Group. Like the preceding groups, they range from the northwest- 
ward to the southeastward. ‘They constitute two parallel lines; the 
northern contains Aitutaki, Atiu, and other Hervey Islands, and ex- 
tends eastward to Rurutu and Raivavai, with the trend N. 66° W.; 
the southern embraces Rarotonga, Roxburgh, and Mangaia, and may 
possibly be continued in Osborn’s Reef and Rapa, with the trend 
N. 65° W. 
f. Samoa or Navigator Group.—The same linear arrangement is 
apparent among the Samoas as elsewhere in the ocean. The trend 
is a little more westerly, or N. 68° W. The easternmost islands give 
a still more nearly east and west course to that extremity of the line. 
But examined on an enlarged chart,* it is obvious that Ofu, Manua, 
and Rose island constitute properly a parallel line, of like trend with 
the three western, and in analogy with the interrupted parallel lines 
of fissures already explained. 
g. Fakaafo or Union Group.—North of Samoa two hundred and 
sixty miles, are three small islands, which le so exactly in a direct 
line, that they merit separate mention. The trend is N. 58° W. 
h. Vadtupu or Elhce’s Group.—To the west of Fakaafo lie seven or 
eight small islands, constituting a line of which the general trend is 
N. 56° W. 
i. Tarawan or Kingsmill Group.—The Tarawan Islands lie under 
the equator, just to the north of the last-mentioned group. From 
Taputeouea, the southernmost, to Maiana (see chart beyond), the trend 
of the range, as well as of the separate islands, is N. 42° W.; and this 
line will embrace the two islands Onoutu and Hurd, one hundred to 
one hundred and fifty miles further to the southeast. The islands 
Hopper, Knox, Charlotte, lie in a line nearly parallel, a little to the 
eastward ; and Peru and Byron’s Islands, one hundred and fifty miles 
to the southeast, have the same direction and a corresponding position. 
The Tarawan Group, taken as a whole, trends N. 25° W. 
j. Marshall Islands, or Radack and Ralck Groups.—The linear ar- 
rangement in the Radack and Ralick Groups is as distinct as in any 
* See the chapter on the Samoan Islands. 
