The African Steamship Company was incorporated in 1852 to carry out a contract with the British Government for conveying the mails monthly to the principal ports of the west coast of Africa and to Madeira and Teneriffe, and also to establish a line of steamers between Sierra Leone and the West Indies. The contract for the mails was entered into by Mr. Macgregor Laird in December 1851, and was for ten years from the ensuing December, commencing with an annual payment of £23,250 and diminishing by £500 a year during the continuance of the contract, thus averaging £21,500 per annum. Five steamers were built for this service by Laird of Birkenhead; they were of iron and were screw-propelled vessels. By 1860 the company was in difficulties and it was proposed to wind it up, but the directors were persuaded to try a service between Liverpool and the west coast of Africa, with excellent results to all concerned for a time, but the control of the company was not too efficient in London and the concern dwindled until, in 1891, it passed into the possession of Elder Dempster and Co., and then progressed even more rapidly than it had previously declined. The Royal Mail Steam Packet Company, who it will be remembered launched their first steamers in 1841, adopted the screw propeller in 1849 when they launched the _Esk_. They were the first to adopt screw propulsion for the conveyance of mails. The company assisted the Panama Railroad Company in 1850 by lending them 125,000 dollars towards the completion of the railroad across the isthmus, and in January 1851 opened a mail service from Southampton to Brazil and the River Plate. Several of their steamers were chartered as transports during the Crimean War. The _Dee_ was chartered in 1860 to the French Government to convey the “Irish Brigade,” which had been raised in Ireland to fight for Pope Pius IX. against Garibaldi, from Havre to Cork on their return from Italy. In the following year the Confederate States commissioners, Messrs. Slidell and Mason, were taken by force in West Indian waters by the Federals from the R.M.S.P. _Trent_. The “_Trent_ affair,” as the ensuing international crisis was called, ended in January 1862, when the company’s _La Plata_ arrived at Southampton with the two commissioners on board. The _Shannon_, one of their steamers, arrived at Southampton in August 1864 from the West Indies with a record consignment of specie, consisting of gold and silver to the value of £1,511,426 in 2207 packages, which was transferred to the Bank of England in forty-one waggons. In 1869 the R.M.S.P. transatlantic steamers extended their voyage from Rio de Janeiro to Buenos Ayres, thus avoiding transfer to smaller vessels at Rio de Janeiro; the _Douro_ being the steamer inaugurating this extension.