DURABILITY OF A HORSE
A horse will travel 400 yards in 4.5 minutes at a walk, 400 yards in 2 minutes at a trot, and 400 yards in 1 minute at a gallop. The usual work of a horse is taken at 22,500 lbs. raised 1 foot per minute, for 8 hours per day. A horse will carry 250 lbs. 25 miles per day of 8 hours. An average draught horse will draw 1,600 lbs. 23 miles per day on a level road, weight of wagon included. The average weight of a horse is 1,000 lbs.; his strength is equal to that of five men. In a horse mill moving at 3 feet per second, track 25 feet diameter, he exerts with the machine the power of 4.5 horses. The greatest amount a horse can pull in a horizontal line is 900 lbs., but he can only do this momentarily; in continued exertion, probably half of this is the limit. He attains his growth in 5 years, will live 25, average 16 years. A horse will live 25 days on water without solid food, 17 days without eating or drinking, but only 5 days on solid food without drinking.
---Burroughs' Encyclopaedia of Astounding Facts and Useful Information, 1889
Groucho Marx (1895-1977)