How Great Generals Win:
The 13 Rules of War from Ancient Greece to the War on Terror

History 361, Longwood University, Farmville, Virginia

The following are numbers that all educated persons should memorize. They will give you handles to make quick estimates of all sorts of things. Here are some examples. You can imagine an acre of ground as being a plot 220 x 200 feet or 44,000 square feet, only slightly more than the 43,560 square feet in an actual acre. You can plot the size of a suburban lot 100 x 150 feet = 15,000 square feet, or a bit larger than one-third of an acre. You can see in your mind the size of 210 acres by imagining a stretch of ground one mile long by one-third of a mile wide (or about one third of 640 acres, which is a square mile). You can convert kilometers per hour to approximate miles per hour by multiplying by .6.

A problem you can solve by logic: The top speed of human beings is about one mile in four minutes. This was the approximately speed that Roger Bannister achieved in May 1954. How fast is that in miles per hour? Using the same logic, what is the approximate top speed in miles per hour of a horse? Note that a Thoroughbred can cover a mile in 1.5 minutes. If you cannot figure these out by logic, send me a query by email, and I’ll show you the easy method.

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