Editing Artillery (section)

====Indirect fire====
{{Main|Indirect fire}}
Indirect fire, the firing of a projectile without relying on direct line of sight between the gun and the target, possibly dates back to the 16th century.<ref>Hogg, O. F. G. (1970). ''Artillery: Its Origin, Heyday and Decline''. C. Hurst.</ref> Early battlefield use of indirect fire may have occurred at [[Battle of Kay|Paltzig]] in July 1759, when the Russian artillery fired over the tops of trees,<ref>Christopher Bellamy, ''Red God of War: Soviet Artillery and Rocket Forces'', London, 1986, p.16, quoted in {{cite book|title=The Dynamics of Military Revolution|last1=Knox|first1=MacGregor|last2=Murray|first2=Williamson|year=2001|publisher=Cambridge University Press|location=New York|isbn=978-0-521-80079-2|page=135}}</ref> and at the [[Battle of Waterloo]], where a battery of the [[Royal Horse Artillery]] fired shrapnel indirectly against advancing French troops.<ref>Against All Odds!: Dramatic Last Stand Actions; Perret, Brian; Cassell 2000; {{ISBN|978-0-304-35456-6}}: discussed during the account of the Hougoumont action.</ref>

In 1882, Russian Lieutenant Colonel KG Guk published ''Indirect Fire for Field Artillery'', which provided a practical method of using [[aiming point]]s for indirect fire by describing, "all the essentials of aiming points, crest clearance, and corrections to fire by an observer".<ref>{{cite book|title=The Dynamics of Military Revolution|last1=Knox|first1=MacGregor|last2=Murray|first2=Williamson|year=2001|publisher=Cambridge University Press|location=New York|isbn=978-0-521-80079-2|page=136}}</ref>

A few years later, the Richtfläche (lining-plane) sight was invented in Germany and provided a means of indirect laying in azimuth, complementing the clinometers for indirect laying in elevation which already existed. Despite conservative opposition within the [[German Army (German Empire)|German army]], indirect fire was adopted as doctrine by the 1890s. In the early 1900s, Goertz in Germany developed an optical sight for azimuth laying. It quickly replaced the lining-plane; in English, it became the 'Dial Sight' (UK) or 'Panoramic Telescope' (US).

The British halfheartedly experimented with indirect fire techniques since the 1890s, but with the onset of the [[Boer War]], they were the first to apply the theory in practice in 1899, although they had to improvise without a lining-plane sight.<ref name="Evolution">{{Cite book|url=https://books.google.com/books?id=5dmYQPNfGFsC&pg=PA30|title=The Evolution of Indirect Fire|author=Frank W. Sweet|pages=28–33|isbn=978-0-939479-20-7|publisher=Backintyme|year=2000}}</ref>

In the next 15 years leading up to [[World War I]], the techniques of indirect fire became available for all types of artillery.<!--To make indirect fire really effective required telegraph or telephone communication...--> Indirect fire was the defining characteristic of 20th-century artillery and led to undreamt of changes in the amount of artillery, its tactics, organisation, and techniques, most of which occurred during World War I.

An implication of indirect fire and improving guns was increasing range between gun and target, this increased the time of flight and the vertex of the trajectory. The result was decreasing accuracy (the increasing distance between the target and the mean point of impact of the shells aimed at it) caused by the increasing effects of non-standard conditions. Indirect firing data was based on standard conditions including a specific muzzle velocity, zero wind, air temperature and density, and propellant temperature. In practice, this standard combination of conditions almost never existed, they varied throughout the day and day to day, and the greater the time of flight, the greater the inaccuracy. An added complication was the need for survey to accurately fix the coordinates of the gun position and provide accurate orientation for the guns. Of course, targets had to be accurately located, but by 1916, air photo interpretation techniques enabled this, and ground survey techniques could sometimes be used.

[[File:Bundesarchiv Bild 183-S36048, Frankreich, Arras, Artillerie.jpg|thumb|German [[15 cm sFH 13|15cm field howitzers]] during [[World War I]]]]
In 1914, the methods of correcting firing data for the actual conditions were often convoluted, and the availability of data about actual conditions was rudimentary or non-existent, the assumption was that fire would always be ranged (adjusted). British heavy artillery worked energetically to progressively solve all these problems from late 1914 onwards, and by early 1918, had effective processes in place for both field and heavy artillery. These processes enabled 'map-shooting', later called 'predicted fire'; it meant that effective fire could be delivered against an accurately located target without ranging. Nevertheless, the mean point of impact was still some tens of yards from the target-centre aiming point. It was not precision fire, but it was good enough for concentrations and barrages. These processes remain in use into the 21st century with refinements to calculations enabled by computers and improved data capture about non-standard conditions.

The British [[Major general (United Kingdom)|Major General]] [[Henry Hugh Tudor]] pioneered armour and artillery cooperation at the breakthrough [[Battle of Cambrai (1917)|Battle of Cambrai]]. The improvements in providing and using data for non-standard conditions (propellant temperature, muzzle velocity, wind, air temperature, and barometric pressure) were developed by the major combatants throughout the war and enabled effective predicted fire.<ref>{{cite book|title=The Dynamics of Military Revolution|last1=Knox|first1=MacGregor|last2=Murray|first2=Williamson|year=2001|publisher=Cambridge University Press|location=New York|isbn=978-0-521-80079-2|page=141}}.</ref> The effectiveness of this was demonstrated by the British in 1917 (at Cambrai) and by Germany the following year ([[Operation Michael]]).

Major General J.B.A. Bailey, British Army (retired) wrote:
{{blockquote|From the middle of the eighteenth century to the middle of the nineteenth, artillery is judged to have accounted for perhaps 50% of battlefield casualties. In the sixty years preceding 1914, this figure was probably as low as 10 percent. The remaining 90 percent fell to small arms, whose range and accuracy had come to rival those of artillery. ... [By WWI] The [[British Royal Artillery]], at over one million men, grew to be larger than the Royal Navy. Bellamy (1986), pp. 1–7, cites the percentage of casualties caused by artillery in various theaters since 1914: in the First World War, 45 percent of Russian casualties and 58 percent of British casualties on the Western Front; in the Second World War, 75 percent of British casualties in North Africa and 51 percent of Soviet casualties (61 percent in 1945) and 70 percent of German casualties on the Eastern Front; and in the Korean War, 60 percent of US casualties, including those inflicted by mortars.<ref>{{citation|first=Jonathan B.A.|last=Bailey|year=2004|title=Field artillery and firepower|publisher=Naval Institute Press|isbn=978-1-59114-029-0}}{{page needed|date=May 2012}}</ref>|J.B.A. Bailey (2004). ''Field artillery and firepower''}}

An estimated 75,000 French soldiers were casualties of friendly artillery fire in the four years of World War I.<ref>General Percin, 1921 ''Le massacre de notre infanterie, 1914–1918''. Percin supports his claim with hundreds of items of battlefield correspondence from all parts of the Western Front.</ref>