The guns were usually deployed on slightly higher ground.
In general, the positions of the infantry and cavalry determined the position for action of the artillery, which usually placed itself in front, on the flanks, and in the intervals between the troops.
The best place for artillery was an open ground without bushes, canals, ditches, hedges, sunken roads etc. These not only restricted the movements of the guns and ammunition wagons but also allowed enemy's infantry to approach the battery unnoticed by the gunners. In 1809 at Aspern-Essling, part of the French Old Guard deployed from 3-rank deep line into a thick skirmish line and took advantage of numerous canals and ditches. They closed to the 50 Austrian guns and delivered a volley. It surprised the gunners so much that they limbered up and hastily withdrew to a position where stood Austrian cavalry.
Position in the wood or near a wooden building, was not the best as there was a danger that the enemy's artillery fire would kick up a hail of splinters or set it on fire. In the defense of village the guns would be placed near a solid chateau, cemetery wall, or stout building.
Usually the guns were deployed on a slightly higher ground.
There were several reasons for this.
- elevation increased range of fire
(However, the more elevated positions caused difficulties
in depressing the barrels and proper aiming.)
- the guns were more immune to ricochet fire
- the gunners had better view of targets
In 1809 at Wagram, many Austrian batteries stood on the "heights" between Neusiedel and Wagram. French soldiers and some artists used this word "heights" to describe this part of battlefield. But these heights were only 5-10 feet above the plain.
Sometimes the guns were deployed on a reverse slope. French artillerist, Senarmont, did it at Eylau in 1807. Arnold writes, ' He assembled a 12-gun battery on a reverse slope where it could fire at the Russians while enjoying partial shelter.' (Arnold "Crisis in the snows" p. 281)
In 1812 at Borodino, the French placed a massive battery of 80 howitzers (howitzers, not cannons) in the ravines of Kolocha River. According to General Yermolov "only the heads of French gunners were seen, and Russian artillery was unable to silence them."
Firing over own advancing troops was not recommended.
Accidents were liable to happen. If any of the projectiles battered the ground before the advancing troops, it made them uneasy and even demoralized them. Especially scary was the premature burst of shell (if the shells had fuses cut short) as it carried destruction among those over whose heads it was intended to pass. The premature exploding shells greatly frightened the horses, causing disorder in the cavalry troops, and weakening their morale. Frederick the Great writes, "Except for when dictated by the circumstances, one never should fire over your own infantry, but rather advance with her ..." In most cases when friendly infantry or cavalry were sent out the batteries ceased fire.
If the gunners were ordered to fire over the heads of advancing troops,
it resulted in so-called plunging long range fire "which had little ricochet".