XV1L INTRODUCTION.. 
Back was mostly: prevented from turning 
his attention to objects of science by the 
many severe duties-which were required of 
him, and which obliged him to travel almost 
constantly every winter that we passed in 
America; to his personal exertions, indeed, 
is mainly to be attributed our final safety. 
And here I must be permitted to pay the 
tribute, which is due tothe fidelity, exertion, 
and uniform good conduct in the most 
trying situations, of John Hepburn, an 
English seaman, and our only attendant, to 
whom in the latter part of our journey we 
owe, under Divine Providence, the preser- 
vation of the lives of some of the party. 
I ought, perhaps, to crave the reader’s 
“Indulgence towards the defective style of 
this work, which I trust will not be refused 
when it is considered that mine has been a 
‘jife of constant employment in my profes- 
sion from a very early age. I have been 
prompted to venture upon the task solely 
by an imperious sense of duty, when called 
upon to undertake it. 
In the ensuing Narrative the notices of 
