From the "Table of Gunnery" given below it would seem that our ancestors' guns were stronger or their powder weaker than ours, the weight of a charge of powder given in it in some cases exceeding half the weight of the shot:—
A Table of Gunnery.
| Weight of Gun. | Weight of Shot. | Weight of Powder. | Range Point blank. | Range Extreme. | |||
|---|---|---|---|---|---|---|---|
| lbs. | lbs. | oz. | lbs. | oz. | yards. | yards. | |
| Cannon Royal | 8,000 | 58 | 0 | 23 | 0 | 300 | 3,000 |
| Demi-cannon | 5,200 | 32 | 0 | 15 | 0 | 300 | 3,000 |
| 24 Pounder | 4,800 | 24 | 0 | 11 | 0 | 300 | 3,000 |
| 12 Pounder | 3,000 | 12 | 0 | 8 | 0 | 295 | 2,900 |
| Saker | 1,500 | 5 | 4 | 4 | 0 | 250 | 2,500 |
| Faucon | 750 | 2 | 8 | 1 | 8 | 200 | 2,000 |
Some Observations on finding the Longitude at Sea.
For want of correct timekeepers, a ship's longitude was, in the time of Queen Anne and for some time afterwards, an unsolved problem. But in the "Compleat Modern Navigator's Tutor, or The whole art of Navigation," published by one Joshua Kelly, of "Broad Street Wapping near Wapping New-stairs," in 1720, we are taught "five of the most rational ways of finding it." The learner is advised, however, "not to confide too much in them, or to omit any of the methods of a sea journal or other precautions to preserve a ship when she nears land." Among these methods eclipses of the moon and Jupiter's satellites of course come first. But of the first of these methods we are told that "it would be accurate and useful if we could have an eclipse of the moon every night," and of the second, that "the impractibility of managing a telescope twelve or fourteen feet long in the tossing rolling motion of a ship at sea, surrounds it with difficulties scarce to be remedy'd."
The craving of these old navigators for some form of good sea timekeeper is shown by Kelly's suggestion for finding the longitude by what he calls "automatas, or unerring clocks or watches," or even by "hour-glasses," directions being given for "preparing and using a very perfect and true-running sand glass, which may precisely run twenty-four hours without error, to be set exactly at noon on leaving the land; which glass upon being run out, is to be turned instantly every day, not losing any time in the turning of it; and so having very warily kept the said glass 'til you think good to make an observation at noon, and having in readiness an half hour, minute, and half minute glass, you may thereby know exactly how much the twenty-four hour glass is before or after the ship's time; the difference being your longitude, east or west, according as the time by the sun is afore or after the time by the glass." Navigation by account, or dead reckoning, has changed little since Kelly's time. Indeed, the use of the chronometer and the perfection of the modern sextant has almost superseded it except in the case of small coasters, &c.
But in Kelly and Woodes Rogers' days the log chip, reel, line, and half minute glass were the mariner's sole means of finding his longitude, or distance, sailed east or west.
Steam and patent logs have much simplified such calculations, which required many corrections not only for leeway but for errors in the log line and glass; "Shortness of the knots in a line," says Kelly, "being on the safer side, that a ship be not ahead of her reckoning; it being better to look for land before we come at it than to be ashoar before we expect it."