Ye rigid Plowmen! Bear in mind
Your labor is for future hours.
Advance! spare not! nor look behind!
Plow deep and straight with all your powers!
The Plow, reported in Bartlett's Familiar Quotations, 10th ed. (1919); reported as The Plough in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 18-19.