It could also be argued that Niccolò Tartaglia's invention of the "gunner's quadrant" (see clinometer) in the 16th century introduced indirect fire guns because it enabled gunlaying by instrument instead of line of sight. This instrument was basically a carpenter's set square with a graduated arc and plumb-bob placed in the muzzle to measure an elevation. There are suggestions, based on an account in "Livre de Canonerie" published in 1561 and reproduced in "Revue d'Artillerie" of March 1908, that indirect fire was used by the Burgundians in the 16th Century. The Russians seem to have used something similar at Paltzig in 1759 where they fired over trees, and their instructions of the time indicate this was a normal practice. These methods probably involved an aiming point positioned in line with the target. The earliest example of indirect fire adjusted by an observer seems to be during the defence of Hougoumont in the Battle of Waterloo where a battery of the Royal Horse Artillery fired an indirect Shrapnel barrage against advancing French troops using corrections given by the commander of an adjacent battery with a direct line of sight.