Early American science writers used the Puritan plain style sermon as a readily available prose model. From the sermon they derived an organization divided into doctrine and uses, a format using sectional divisions and heads, the use of simple language, and a concern for the needs of their audiences. Essays on comets by two early American scientists, Samuel Danforth and John Winthrop, illustrate the sermon's influence. The doctrine and uses organization employed in these essays may be seen as analogous, in some senses, to the Results and Discussion organization of the modern research report.