The protection of orchards in the Pacific Northwest from spring frosts by means of fires and smudges - O'Gara, P. J. (U.S. Dept. of Agriculture, 1910)
Preparation necessary for frost prevention -- Materials to be used for fuel -- Materials for starting fires -- Manner of distributing the materials in the orchard -- Quantity of material to be used for each fire -- Cost of materials for firing an acre -- Necessity of understanding weather conditions -- Meteorological data obtained in the Rogue River Valley -- Weather conditions producing spring frosts in the Rogue River Valley -- Injurious temperatures -- Results of the work -- Value of firing the orchards when the cost is compared with the value of the crop -- Practical suggestions on the use of psychrometer and other meteorological instruments