"How did pickets/outposts work in Napoleonic armies?" Topic

I'm thinking of an advance guard for a column being ordered to establish a chain of outposts ahead of the main body.

Specifically, how much front would say a battalion of light infantry (or squadron of light cavalry) be expected to cover on outpost duty, and what would be the number and relative strength of posts it could furnish?

What was the typical spacing between the forwardmost individual sentries?

What would be the frontage of the whole outpost system relative to that of the forces to be covered? [i.e. if a corps is being covered, would its vanguard's outposts be expected to extend 2km or so to match the whole deployed frontage of the corps?]

Do you have, or have access to, Antoine de Brack's Cavalry Outpost Duties?

I could probably find it if it's on Gallica or Hathitrust or some other site like that.

Cavalry outpost duties.
By F. de Brack … Translated from the third French ed., 1863, by Major Camillo C. C. Carr.

New York, J. Wiley & sons, 1893.
link

For de Brack, the subject is covered on pages 119-133, entitled Grand Guards, Pickets, Small Posts, and Patrols. Advance Guards are covered on pages 143-150. Reconnaissance is covered on pages 151-171. There is also a short two page (117-118) on The Pipe and why 'Every trooper should be encouraged to smoke a pipe.'

The following, from John Elting's Swords Around a Throne, page 544, should also be helpful in answering the question:

'Moving or halted, the Grande Armee's front and flanks were protected by its cavalry screen. On the flanks, light cavalry squadrons were sent out from 10 to 15 kilometers to form based from which small patrols probed farther outward to collect information concerning the enemy. Around the head of the army was a thicker screen. Once halted for the day cavalry regiments sent out security detachments to establish 'grand guards' well in advance of their positions. The grand guards each sent out several 'petits postes' (outposts), which in turn sent forward several vedettes (mounted sentinels). All of those were placed so as to cover the various roads, paths, and stretches of open ground leading into the army's position. During daylight vedettes were posted on high ground for better long-range observation; at night they were shifted to lower ground from which they watched the skyline before them for any indication of enemy movement. Two-man patrols moved among and beyond those stationary posts. (in some cases they might replace the vedettes.) They rode quietly and carefully, keeping an eye on the ears of their horses, which often detected a concealed enemy much sooner than their riders.'

'If the enenmy advanced, the vedettes and patrols gave the alarm and fell back on the outposts. If the advance was in some strength, the outposts retired on the grand guards, which meanwhile had mounted ready to fight. Grand guards could handle small enemy parties; at worst, they could gain time for the main body to get under arms and form up. When the enemy's main army was close at hand and its troops were active, an inner line of piquets (pickets) might be set up behind the grand guards to support them and furnish patrols. In heavily wooded or broken country the grand guards and pickets would include infantry detachments. Beyond this outpost system, cavalry detachments would be on the prowl en partisan (using guerilla tactics) within the enemy lines to pick up information and prisoners.'

I could probably find it if it's on Gallica or Hathitrust or some other site like that.

You can find it for download here:

link

Thanks for the links. Sadly, they don't seem to have quite the specifics I'm looking for; I'd like to get to the point I could diagram a chain of outposts more or less down to the man.

I asked myself the same q. Conclusion is that it depends so much on terrain: passable or not, can you see far away? , day or night… what can you expect, that there hardly can be an iron rule.
Tyere are other books with bits or more on petite guerre plus even say the Austrian regulations that have some. Have to look further, but lazy and afraid my conclusions will end up the same.
Maybe if you don't have a detailed terrain, take half the numbers in vedettes etc, then roll a D6 for each sdn and less # means closer terrain, multiply by so many 500m or so.