Ballistic dial sight

myminifactory

The presented object is a ballistic kit used in field artillery for aiming and setting the target axis of the cannon. It consists of two elements: a sight and a quadrant, stored in a wooden case. The two-part sight has an extendable middle element, scaled in the range of 1–13 inches with 1/4-inch accuracy. Three vision holes enable the height of the points describing the target to be specified [1] . The kit was placed on the cannon's sight and verticalized using a large pointer. The quadrant has the form of a square plate with an indicator. The scale is two-sided, in the range of 0–90° with an accuracy of 1°. The apparatus was attached to the bottom of the barrel, sometimes fixed to a wooden rod. It was used to determine and set the elevation angle of the barrel in order to obtain the appropriate departure angle of the projectile. The collection of scientific instruments located at the Jagiellonian University Museum includes didactic, scientific, as well as everyday items. In addition to wall clocks, controllers, measures, weights, telephones or cameras, one can also find medical, measuring and military instruments. The dial sight had been used in artillery since the 16 th century. It allowed for accurate gun laying. The process was quite complex. The first step was to accurately aim at the target (using a sliding ruler placed on the cannon's sight), then calculate the amount of gunpowder and the elevation angle of the barrel. Finally, the barrel was positioned by checking its inclination angle on the quadrant scale. In more contemporary instruments, the sight and quadrant were already combined into one instrument. One of the first descriptions of the use of military quadrants comes from La Nova Scientia by Niccolò Tartaglia (Venice 1537), and the use of artillery sights to determine the target location and laying the gun was described by Leonhard Zubler in Neuwe geometrische Büchsenmeisterery (Zurich 1608).