The new method of fortification, as practised by Monsieur de Vauban, Engineer General of France with an explication of all terms appertaining to that art / made English.

I. To take the Vertical Height of any thing, when you can come to the bottom.

Let the height of a Tower AB be to be measured.

1. Draw a right Line as you please from the point A, a•• AC.

2. Measure the Line AC with your Scale, or your Chain•• of 26 Feet for instance.

3. Set the Staff, upon which the Astro∣labe is Horizontally fastned, upon C, so that by the fixed Sights, one may see the Line CA, from one end to the other, as fas as the Tower, and that by the two other mo∣vable sights the point B, which marks the height of the Tower, may also be seen.

4. When the Instrument is thus fixed, com∣pute whether the Angle CDE be 40 degrees.

5. Then draw upon Paper a right Line of the length of AC, as FG: But this must be done by a small Scale made upon the Pa∣per, or by a Scale of Wood or La••ten: Af∣terwards erect a Perpendicular upon G.

6. Take the Reporter [the French word is Rapporteur] and set it directly upon FG, so that the middle of it may answer to the point F: then compute an Angle of 40 De∣grees equal to CDE, as FHI.

7. From F draw a right Line thro•• I, ••ill it touches the Perpendicular G in K.

8. With a small Scale measure the height of KG, and add the height of the Staff to which the Astrolabe is fastned, and the Sum will give you the height of the Tower AB.