Gerhard Moritz Roentgen (* 7 May 1795 in Esens in Ostfriesland; † 28 October 1852 in Santpoort near Velsen in North Holland) was a Dutch Navy officer, machine building engineer and ship builder. As of 1823 he was involved in founding the Nederlandsche Stoomboot Maatschappij (NSM). At first he was one of NSM two chief executives. Later on, he was the only executive till 1849. The invention of the marine compound steam engine is Roentgen's main scientific achievement.
Early life
Youth and service in the navy
Gerhard Moritz Roentgen, known in the Netherlands as Gerhard Mauritz Roentgen, was the fourth son of Ludwig Roentgen and Sophia Margaretha Tischbein. Ludwig was a minister and the inspector of the orphanage and poor house in Esens, Ostfriesland. Ludwig's father descended from the artistic cabinet maker family Roentgen from Neuwied on the Rhine.
Till his 13th year, Roentgen lived in Esens, which had become part of the Kingdom of Holland by then. In 1808 he joined the Dutch naval academy in Enkhuizen, which he left as midshipman in 1810. Together with 30 other students, Roentgen was sent to Toulon by the French, where they should finish there education. When they applied to leave the French service in Spring 1814, the students were jailed in a fort near Toulon. Roengen escaped with two others, and arrived back in Holland in Summer.
In 1813 the Netherlands had been liberated. Roentgen then joined the re-established Dutch navy. In November 1814 he became a lieutenant 2nd class. In 1815 he sailed to the Dutch East Indies on board the ship of the line Brabant. The shoddy ex-French Brabant was forced to enter Portsmouth on 31 October 1815. Here she was docked and then sent back. Roentgen remained in England with orders to study shipbuilding there. In England Roentgen met the engineer John Fincham (1785-1859) and several others, just when the first steamboats were built there. In 1817 Roentgen became adjutant of the naval commander of Rotterdam.
In March 1818 Roentgen and the engineers C. Soetermeer and C.J. Glavimans got orders to make a more regular research trip to England. Roentgen remained in England till October 1820. He had a full permit from the British government to visit the navy shipyards, and to draw and model everything.
Marriage
In England Roentgen became acquainted with the very beautiful Georgina Louise Bennet (+1795-?). Without requesting the customary permission from the king, Roentgen married Georgina in 1821. He later apologized to the king for this unthoughtful act, and the king forgave him. However, his wife had to come to the Rotterdam Navy Command on 21 May 1821, and promise never to join her husband on a sea trip or on board ship.
Orders the Moerdijk ferry
In August 1821 Roentgen got net orders to go to London. He was to design and order ferry steamboat for the Moerdijk.
Role in modernizing the Belgian iron industry
The Belgian iron industry had flourished during the French period, when British iron was banned from the continent. After the regained independence, it was getting obliterated by the British competition. The British product was so much better and cheaper, that the Netherlands could not do without it. Therefore, the government wanted to know why the Southern Netherlands iron industry could not achieve the same quality. The government lacked a true expert, and then gave Roentgen the far wider mission to also gather all possible information about the British iron mining, production, and processing.
Roentgen instructions held that he should primarily focus on how the British iron became so pure by removing other minerals like copper, zinc, arsenic and phosphorus. He furthermore had to study blast furnaces, the cupola furnace, rolling, and the use of coal in smelting iron. For some months Roentgen travelled in the English and Scottish industrial heartlands. In August 1822 he sent in his report. He noted that the British iron was so superior because it used Limonite as ore, instead of trying to purify other ores. The use of limonite was connected to using blast furnaces, and cokes or coal as fuel.