The third part of the principles of the art military practised in the warres of the United Provinces vnder the Lords the States Generall and His Highnesse the Prince of Orange : treating of severall peeces of ordnance ... : together with a list of all necessary preparations appertaining to an armie ... / written and composed by Henry Hexham.

HOW A CANNONIER OVGHT TO LAY AND Levell his Peece and to amend a bad shott, CHAPTER VII.

HAving time and Command to lay and Levell a Peece, according to the ordinary ayme, to try how farr it will carry, the Canonier shall take a long ruler, and laying it vpon the midst of the Frizes, aswell of the brich, as of the muzzle of the peece, and a levell upon it, he shall raise or sinke it, untill the plummet of the Levell be iust in the midst: then taking away both the Ruler and the Levell, he shall see even with the Frizes, the point or marke which this ayme discovers, which without doubt will be the place it wil carry to; with which accor∣ding to the levell of the mettell, whereof wee will speake hereafter, it will make but the half. But if he hath no leisure so to use the Ruler and Levell, he may take his ayme, or lay his peece, as he finds good, according to the charge and proportion of his peece. If he strickes his marke, he may then be assured, that his ayme is right, and using the like weight of powder, will alwaies make the same shot.

But if his bullet carries over, he shall level his peece againe as he did before, and having got the first marke in his sight, he shall neither stirre nor mooue his peece: but shall take away asmuch of the Frizes of the brich, till he sees the blow which the bullet gaue, and which will bee the true, and right sight, which he presently may trie by laying his peece upon his first marke, which without any doubt he will strike.

Now if his first shot fals short, then he must doe as he did before, levelling his peece again and then without mooving it, he shall goe and take away the Frizes from the muzzle till hee discovers the blow of the bullet, and then he shall haue the true sight; according to which, laying his peece upon the first marke, hee will surely strike it, if that there bee no fault in the powder.

There is an other way of levelling of a peece, and amending of a bad shott, in adding or di∣minishing the elevation, according to discretion. To witt, when he shootes short of his mark, the peece is remooved and layd as before, afterward he raises up the Muzzle as he shall judg, and as need shall require, that he may strike his desired mark, observing well alwaies how much this elevation is made higher then his first ayme taken, which he shall perceiue if looking even with the mettell, he shall see what marke it will show him.

How a Canonier ought to Levell his Peece.

Then giving fire, and striking the marke before aymed at, he may be assured, that his peece carries right, to which henceforward hee shall giue as much height aboue the naturall Levell: if it failes, that is, if he over shootes his marke, let him dispart that which his firstshot fell too short, with the length of the same, for the lessening of the Elevation proportionably; in doing whereof, without all question hee shall see his shott remedied, and a right shott made. And this is your common and ordinary way in which Gunners do most exercise themselues in, with assurance that he which knowes not by this meanes to giue the right elevation and range to his peece, is not worthy of the name of a Canonier. Now for his better understan∣ding I will giue him this example.

Suppose a canon be mounted upon his carriage, and planted upon a plateforme, and is to mark a shot at some white-stone or marke in a Wall. To doe this, your Gunner must take his ayme as curiously as possibly he can Levell with the mettell of his peece, but if his shot fals to short, to helpe it he shall take his ayme againe, and shall lay his peece as hath beene taught before: afterward he shall raise it a point higher, so that whereas he had but 6. before, now he hath 7. points of the elevation, and afterward giues fire. If he striks his mark let him alwaies take the same ayme and Levell, But if he over shootes his marke, let him levell his peece as is taught before: by disparting the difference of the first, from 6. with that of seven points, as discretion shall guide him, according to the carriage of the first shot, and giving fire, (without all doubt) he shall hit his desired marke. And his Peece being thus raised he must keep in his sight the point or marke which is showne him, and obserue wel the height which is aboue his marke, with assurance that when he is to make more shot by keeping this elevation he wil never faile. But if the first shot lying upon the 6. points be to high, then he shall helpe that by the same Rule in laying his peece lower, and so shall strike his marke whereby he shall get credit and commendations for it.

A new devise by any staffe, to levell, mount, and imbase any peece.

ALso any peece may with a field Linstock, Rammer, or Spunge, or other staffe be moun∣ted to any degree of the Quadrant, being thus prepared, first mark from one end of that staffe a distance equal unto the height of the pomel or caskabel of the peece, placed levell upon her platform, & then take the distance between the centre of the Tronions, and the po∣mell or caskabell, which make or imagine a semidiametre of a Circle, and divide it by diago∣nals or paralels, or otherwise into a 1000. equal parts. Lastly out of the table of Sines, take the number answering to every degree out of the said 1000. parts, and set that distance from the said mark downwards, and if the totall Syne of the table be 100000. omit the two last figures of each number thereof toward the right hand, and if it be 10000000. then omit 4. figures of each number you find in that Table, and the remaining number will shew how many of those 1000. equall parts are to be set downwards from the mark beneath the said levell for each severall degree: Then drawing also 10. paralels or diagonals from the first degree to the second, and from the second to the third, &c. successively continued from each to his next, no∣ting every degree with Arithmeticall characters, so you may from six minutes to six minutes by those right signes mount the peece, so set forth for any peece which it shalbe prepared for. This may also be described upon such a staffe without the table of synes in a mechanical man∣ner thus, If you describe a Quadrant or quarter of a circle with a semidiametre, equall to the distance from the centre of the trunions, to the centre of the pomel or caskabel, & devide the Arch of that quadrant into 90. equall parts or degrees, and then from each degree letting a line fall perpendicularly upon the base side of the said quadrant, and lastly, each of those right lines being thence transferred from the said first marke downwards upon the said staffe, and marking them with arithmeticall figures for each degree, thereupon making also paralels and Diagonals as aforesaid, you may thereby Geometrically and mechanically marke the same from 6. to 6. minutes as before. The use of them is plain and easie, for if you bring downe the centre of the caskabel or pomel of the peece to any number of the degrees thereon so mark∣ed, for that peece, you setting the lower end of the staffe to the platform being even, although it be rising or descending backwards, I say then the axis of the bore of that peece wilbe found to be elevated to the degree assigned: If you be to imbase the peece, those lines and number also set above the first named mark, will perform the like office there, in the thing required.