One of the first notable steamship lines to be organised for oversea service was that which ultimately became the Peninsular and Oriental Company. It had its origin[36] in steamship service from Falmouth to Oporto, Lisbon, Cadiz, and Gibraltar. Four steamers were built in 1836-37: the _Tagus_, _Don Juan_, _Braganza_, and _Iberia_. The first-named was built by the Scotts, and the third was engined by them. These ultimately carried the mails as far as Alexandria, whence they were conveyed overland to Suez, and from thence by the East India Company's vessels to Bombay. This service developed into the Peninsular and Oriental service, when, in 1840, the Company took over the mail service on the Indian Ocean; in 1847 they extended their operations to China. The overland service continued until the Suez Canal was opened in 1869, and many of the vessels for the Mediterranean service, as well as for the eastern route, were built by the Scotts. [Illustration: Plate X. SCOTTS' FIRST P. AND O. LINER, THE "TAGUS."] The _Tagus_,[37] which was thus amongst the first of the P. and O. steamers, was built in 1837. She had a length of 182.1 ft., a beam of 26 ft., and a depth of 17 ft. 4 in., the burden tonnage being 709 tons. When carrying 265 tons of coal in her bunkers and 300 tons of cargo, the draught was 14 ft. 6 in. The side-lever engines which were fitted to her had a cylinder 62 in. in diameter, with a 5-ft. 9-in. stroke, developed 286 horse-power, and operated paddle-wheels 23 ft. 6 in. in diameter. Two of the other early steamers, the _Jupiter_ and the _Montrose_, were also constructed by the Scotts. The conveyance of cargo and passengers across the Isthmus of Suez not only involved inconvenience and expense, but was a cause of great delay. There was still, however, a strong prejudice against steamships being utilised for long sea voyages, partly because of vested interests in sailing ships. Sir John Ross, C.B., who, in 1818 and in 1829 to 1833, made Arctic explorations, was one of the strongest advocates for a service to India by way of the Cape of Good Hope; and, in order to establish the feasibility of the undertaking, made experiments with the _City of Glasgow_, built by the Scotts in 1821. This vessel, of 283 tons, had in the interval been fitted with new boilers, with special safety appliances, and they worked at 4-lb. pressure; they gave the high evaporation in those days of 9 lb. of water per pound of coal.[38] This vessel made the trip from London Bridge to the lightship off Spithead (246 miles) in thirty-one hours five minutes, on a consumption of 6 lb. of fuel per indicated horse-power per hour. These facts were utilised by Sir John Ross in his advocacy of the route, and a new company was formed, under his chairmanship, in 1837.