Farmers' bulletin (United States. Dept. of Agriculture); no. 401

"The object of this bulletin is to give, in considerable detail, the results of successful experiments and the methods employed in preventing frost injury by means of fires and smudges in the apple, peach, and pear orchards of the Rogue River Valley in southern Oregon during the spring of 1909.... The important facts to be known by the grower are how to prepare for frost prevention, what materials to employ for fuel and the manner of distributing them in the orchards, what to use in starting the fires and the method of preparing them, etc." -- p.