I back-tripped it four times a day, and on each forward trip carried one hundred and fifty pounds.

This means that over the worst trails I daily travelled twenty-four miles, twelve of which were under a burden of one hundred and fifty pounds.
Yes, I had let career go hang, and was on the adventure-path again in quest of fortune.

And of course, on the adventure-path, I met John Barleycorn.

Here were the chesty men again, rovers and adventurers, and while they didn't mind a grub famine, whisky they could not do without.
Whisky went over the trail, while the flour lay cached and untouched by the trail-side.
As good fortune would have it, the three men in my party were not drinkers.

Therefore I didn't drink save on rare occasions and disgracefully when with other men.