Cornelis Rudolphus Theodorus Krayenhoff

Corneli(u)s Rudolphus Theodorus (from 1815 Baron) Krayenhoff (Nijmegen, 2 June 1758 - Nijmegen, 24 November 1840) was a physicist, artist, general, hydraulic engineer, cartographer and - against his will and for only a short time - Dutch Minister of War.

Biography
His father was a hydraulic engineer and soldier in Nijmegen, with brewing as a sideline. Krayenhoff received his training in Nijmegen, Arnhem and Harderwijk. In that city, he got to know H.W. Daendels. He had been intended for the jurisprudence, but began to study philosophy and medicine instead (1777-1783). In his dissertations he wrote on the  theory of the imagination and a medical survey of the dysentery that was raging in Nijmegen in 1783. He established himself as a physician to Amsterdam, after he had refused an offer to be a professor in Franeker. He was a member of the genootschaps of Concordia et Libertate and Maatschappij tot Nut van het Algemeen. In the genootschap Felix Meritis he gave lectures, on physics experiments and art history. At the request of the Defensiewezen in Amsterdam, he was put in charge of organising the floods around the city. As a result of the chaos, the Patriots could not stop the Prussian army in October 1787.

Krayenhoff was an authority on electricity and lightning. The tower of the Grote of Martinikerk in Doesburg was, in 1782, the first building in the Netherlands to get a lightning conductor. He and Adriaan Paets van Troostwijk in 1787 won first prize for their article on electricity. In 1791 he became member of the Hollandsche Maatschappij der Wetenschappen.

The Batavian Republic
At the end of 1794 Krayenhoff is named as in service in the French army. He had had to flee Amsterdam secretly because he was involved in gathering weapons in Amsterdam. (Was it the Bickerseiland, or was it Roeters island as Simon Schama marks down?) On Sunday afternoon 18 January 1795 - at Daendels' instruction - he came to tell Amsterdam's mayors that they could better resign the next day. The leading Dutch patriots, like Samuel Iperusz. Wiselius, Krayenhoff, and Nicolaas van Staphorst requested general Charles-François Dumouriez to plant the liberty tree in The Hague or on the Dam square and to bring about liberty, equality and fraternity by force. The Patriots did not want to leave everything to the French, because they would then get less say in the matter. After the revolution that formed the Batavian Republic, he struck out on a political and military career.

In 1796 he became head of the Dutch fortifications and moved to Muiden. From 1798 he was involved in organising the new Rijkswaterstaat, after the sovereignty of the provinces was lifted. He saw the campaign against the Russian-English invasion of 1799 by (see Battle of Castricum) and advised the army leadership. Krayenhof was meanwhile beginning his life's work : the driehoeksmeting, so that the Netherlands could be mapped in detail.

Krayenhoff busied himself with determining the Amsterdam Level. Louis Bonaparte was very taken with him and gave him various positions. Krayenhoff was for ten months Minister of War and organized Amsterdam's apology for her resistance. This caused an imminent invasion of Napoleon Bonaparte. Krayenhoff took his first stand on the Stelling van Amsterdam, at the Posten van Krayenhoff, called by some the Oude Stelling van Amsterdam. When Napoleon came this to point, Krayenhof had to be fired. In a meeting, Napoleon still showed interest and appointed him in Paris. Krayenhoff got an attractive offer from Russia, but feared the tsar, for his two sons had been captured in Russia in 1812 and were still in captivity. His eldest son fought in the Battle of Waterloo against Napoleon, and was wounded.

Willem de Clercq mentions in his diary that Krayenhoff gave the order that, should there be a French attack, "...every man should take his threshold, carry it to his front room, and greet the attacking French sweetly with a rain of stone" ("aan iedereen om de stenen voor zijn deur op te nemen, dezelve op zijn voorkamer te transporteren en daarmee de aanvallende Fransen lieflijk met een steenregen te begroeten"). In 1813 he worked diligently for the Restoration and in 1815 he was made a baron.

In that same year, he took the initiative on the New Dutch Water Line, assisted by Jan Blanken. In 1818, Krayenhoff got into problems regarding the building of defence works in Charleroi. His youngest son, Johan Krayenhoff, was involved in the building of the fort in Nijmegen. In 1825 he travelled on a frigate to Surinam and Curaçao.

Krayenhoff got into more problems in 1826 over alleged dishonesties committed in the construction work and its on the strongholds in Ieper and Ostend, but was acquited in 1830. On 12 May 1823, Krayenhoff was appointed Knight Grand Cross in the Order of William for his contribution to the strengthening of the Netherlands' southern border. From 1826 he left active service and wrote his memoirs. Krayenhoff passed away on his 82nd birthday and is buried at the Rustoord in Nijmegen.

Works

 * Paets van Troostwijk, A. & C.R.T. Krayenhoff (1787) De l'application de l'electricité à la physique et à la médecine.
 * Verz. van hydrogr. en topogr. waarnemingen in Holland (1813)
 * Précis historique des opérations géodésiques et astronomiques faites en Hollande (1815)
 * Proeve van een ontwerp tot scheiding der rivieren de Waal en de Boven-Maas (1823)
 * Geschiedk. beschouwing van den oorlog op het grondgebied der Bat. Republiek in 1799 (1825)
 * De Lt.-gen. Bn. Krayenhoff voor het Hoog Mil. Geregtshof beschreven en vrijgesproken (1830)
 * Bijdr. tot de Vaderl. gesch. van 1808 en 1809 (1838)