Machine Gun - The Story of the Men and the Weapon That Changed the Face of War (Paperback, illustrated edition)

Richard Gatling, the one-time philanthropist, had been stung by growing competition. In 1881 he published a forthright challenge in the Army & Navy Journal.
The Gatling Gun
Many articles have recently appeared in the press, claiming the superior advantages of the Gardner and other machine guns over the Gatling gun.
In order to decide which is the best gun, the undersigned offers to fire his gun against any other gun, on the following wagers, viz.:
First, $500 that the Gatling can fire more shots in a given time, say one minute.
Second, $500 that the Gatling can give more hits on a target, firing, say one minute-at a range of 800 or 1,000 yards.
The winner to contribute the money won to some charitable object.
The time and place for the trials to be mutually agreed upon.
R.J. Gatling of Hartford, Conn.
No one took up the challenge, possibly because the various purchasers of these guns had made up their own minds about the merits of the rival weapons. Nevertheless, of all the rapid-firing guns in business at the time, the Gatling had pride of place. It was seeing service all over the world, and perhaps Gatling should not have bothered to express such apparent nervousness. What he did not know, and could not then know, was that an electrician working out of New York City would soon serve as the greatest rival of them all. Three years after that gamble had been published in the Journal, Hiram Stevens Maxim would be travelling to Europe. There he would appreciate quite how many nations were rattling sabres at each other, and hear his friend's advice that, if he wished to make money, he should help their citizens kill each other. And that is what he did. The 'greatest mechanician of all' would change warfare dramatically, and the first fully automatic machine gun would eclipse all others.