That fire in the woods in Groton on the 27th, which was seen so far.

April 30. 

Cattle begin to go up-country, and every weekday, especially Mondays, to this time [sic] May 7th, at least, the greatest droves to-day. Methinks they will find slender picking up there for a while. 

Now many a farmer's boy makes his first journey, and sees something to tell of, — makes acquaintance with those hills which are mere blue warts in his horizon, finds them solid and terra firma, after all, and inhabited by herdsmen, partially befenced and measurable by the acre, with cool springs where you may quench your thirst after a dusty day's  walk.

Surveying Emerson's wood-lot to see how much was burned near the end of March, I find that what I anticipated is exactly true, — that the fire did not burn hard on the northern slopes, there being then frost in the ground, and where the bank was very steep, say at angle of forty-five degrees, which was the case with more than a quarter of an acre, it did not run down at all, though no man hindered it.

That fire in the woods in Groton on the 27th, which was seen so far, so very dun and extensive the smoke, so that you looked to see the flames too, proves what slight burnings it is, comparatively, that we commonly see making these cloud-like or bluish smokes in the horizon, and also how very far off they may often be. 

Those whitish columns of smoke which we see from the hills, and count so many of at once, are probably often fifty or sixty miles off or more. I can now believe what I have read of a traveller making such a signal on the slope of the Rocky Mountains a hundred miles off, to save coming back to his party. 

Yet, strange to say, I did not see the smoke of the still larger fire between Concord and Acton in March at all, I being in Lincoln and outdoors all the time. 

This Groton fire did not seem much further off than a fire in Walden Woods, and, as I believe and hear, in each town the inhabitants supposed it to be in the outskirts of their own township.

H. D. Thoreau, Journal, April 30, 1860

Cattle begin to go up-country. See  May 10, 1852 ("This Monday the streets are full of cattle being driven up-country, — cows and calves and colts."); May 6, 1855 ("Road full of cattle going up country.”); May 7, 1856 ("For a week the road has been full of cattle going up country.")

That fire in the woods in Groton on the 27th was seen so far. See April 27, 1860 ("There is a large fire in the woods northwest of Concord, just before night. . . .One who had just come down in the cars thought it must be in Groton, . . . So hard is it to tell how far off a great fire is")

The still larger fire between Concord and Acton in March. See March 31, 1860 ("I hear that there has been a great fire in the woods this afternoon near the factory. Some say a thousand acres have been burned over.")