vm PREFACE. 
and in one instance alone a reduction of 12' in the chart was obtained. 
It is said in Hawkesworth (III, 202), " As soon as we got within 
side the reef (through Providential Channel) we anchored in 
nineteen fathom;" and afterwards (p. 204), that the channel 
" bore E. N. E. distant ten or twelve miles." In the first chart 
the distance is 14! miles, and nearly the same in that which accom- 
panies the narrative; but in the log book it is said to be 2^ miles only, 
which corresponds with having anchored as soon as they got within 
the reef, and has been adopted. In some cases it was not easy to 
make a choice between these different authorities ; but I have com- 
monly followed the narrative and log book when they were found 
to specify with precision, and they generally produced such 
corrections to the chart as brought the longitudes of places nearer 
to my positions. Captain Cook's track in Plates XI. XII. and XIII, 
is laid down afresh from the log book ; and many soundings, with 
some other useful particulars not to be found in the original chart, 
are introduced, for the benefit of any navigator who may follow 
the same route. 
The reconstruction of the charts in the Atlas was done upon 
various scales, but that no error might escape unseen, the least was 
of ten inches to a degree of longitude ; they were then reduced 
by Mr. Thomas Arrowsmith to four inches, this being thought 
sufficiently large for a general sailing scale ; and each reduced 
sheet was scrupulously compared by me with the original before 
it went into the engravers hands, and the proof impressions with 
the drawing until no errors were found. To those who may read 
this voyage with a view to geographical information, a frequent 
reference to the Atlas is earnestly recommended ; for many par- 
ticulars are there marked which it would have been tedious to 
describe, and should any thing appear obscure in the narrative the 
charts will generally afford an elucidation. 
