lasted from 15 July to 20 September and was supervised by Rear Admiral Hyde Parker. The trial was part of a series that attempted to compare new methods of ship building with traditional ones. Cumming at last received promotion to Commander on 9 November 1846. His first command was HMS Rattler, a 12-gun sloop that had been the first warship powered by a steam engine and screw propeller, that he captained from 12 February 1849 to 15 April 1851 on the west coast of Africa. Whilst in command of Rattler Cumming captured the Brazilian slave brigantine Alepide on 30 October 1849. In 1853 Cumming married Adelaide Stuart with whom he had at least one child. Crimean War Cumming saw active service against the Russians during the Crimean War. On 25 February 1854 he received command of the frigate HMS Gorgon, being promoted to post-captain on 19 April. Cumming was transferred to command HMS Conflict on 9 May 1854 and served aboard her in the Baltic Sea until 6 February 1855. In company with HMS Amphion, under the command of Captain Astley Cooper Key, the Conflict sailed into Libau on 17 May 1854. The harbour contained eight Russian merchant vessels and was defended by a force of 4–500 soldiers with 2–3 cannon. Cumming went ashore under a flag of truce to meet with the town's governor and demand the handing over of the merchant ships within three hours. The governor refused to comply but the Russian troops left the town shortly afterwards and the governor stated that, whilst he could not order them out of the harbour, Cumming and Key would be permitted to enter the harbour to take them. They proceeded to do so, finding themselves in control of the entire town of 10,000 inhabitants with just 110 men, and took out the eight merchant vessels without firing a shot. The ships were sent with prize crews to the Prussian port of Memel. Cumming and Conflict also saw service at the port of Riga in this period and from 15 April to 22 May were responsible for boarding 19 vessels. Cumming returned to England in 1855 and on 22 May was appointed to HMS Glatton, an ironclad floating battery with orders to sail her to the Black Sea. He carried out these orders but arrived after the end of the war and returned Glatton to the United Kingdom by Spring