The speed at which armies operate is a crucial factor in understanding their supply demands.
Written by Count Yegor Frantsevich Kankrin (Егор Францевич Канкрин) (16 November 1774 – 10 September 1845) as a three volume set in 1820, it followed his service in the Russian Army as a Commissary during the Napoleonic Wars. In 1823, he was appointed Finance Minister, a post he would hold for the next 21 years, his most singular achievement being the reform of the Russian currency.
His book on military supply expands on Clausewitz's theme that armies can best live by requisitioning from the local authorities and can, in most circumstances live without magazine supply, which he considers limits the manoeuvrability of armies. However he goes further than Clausewitz, giving detailed statistics on the availability of supplies in seven categories of terrain from highly cultivated lands to desert, with examples of actual countries or provinces that correspond to these categories. Using these statistics and calculations on the supply requirement of a typical corps, he shows the method of supply needed for each of these terrain categories, highly cultivated terrain can support a corps by requisitioning and quartering, medium cultivated terrain is the same with the support of some magazine supply, lightly cultivated terrain requires magazine supply and limits the size of the army, while semi-desert and desert can only support small forces.
Bibliographic listing: Kankrin, Y. F. Uber Die Militairokonomie Im Frieden und Krieg, und Ihr Wechselverhaltniss zu den Operationen.
Krankrin's book is unclear as to the area of land required by his typical Corps for foraging in his seven categories of terrain and their associated population density. However Clausewitz does give an indication of the area of land needed to sustain a Corps of 30,000 men for a couple of days when the population density is 2,000-3,000 inhabitants per Q Meile (35-55 people per km sq) which is a square of 2 Q Meile sides (15 km) or an area of 4 Q Meile (225 km sq). By combining these two approaches it is possible to quantify Krankin's model.
|Number of troops sustained by certain levels of population density – Kankrin methodology|
|Population density inhabitants per Q Meile||Population density (inhabitants per km2)||Foraging square of 2 Q Meile (15 km2)||Countries 1820||Supply method|
|Area||4 QM or 225 km2|
|Medium cultivated||1,500||26||24,000||Poland||Requisition & Magazine|
|Medium cultivated||1,000||18||16,000||Spain||Requisition & Magazine|
|Little cultivated||800||14||12,800||Russia||Magazine supply|
|Semi-desert||300||5||4,800||Turkey||Unsuitable for large armies|
|Desert||150||3||2,400||Mountains||Short distances for small corps|