Commercial steam propulsion had been around from the early 19th century, the first regular passenger service in Europe was established in 1812 with the Comet between Glasgow and Helensburgh. Following British innovations the Americans developed steam vessels for use on their extensive inland waterways and lakes which, among other things, was the only practicable way to gain access to vast tracts of previously inaccessible territory. In the U.K., inland waterways approached full development at about the same time as the development of the railways which offered greater commercial prospects rendering inland waterway steam transport redundant almost as soon as it was introduced.
The real opportunity for steam in the Great Britain lay in reliable intercontinental, rather than merely coastal, shipping bearing in mind how much of the world map was then coloured pink. Before about 1815 steamers were neither strong enough nor sufficiently powerful to be of use in open sea. The first regular sea-going steamship was the Rob Roy on the Glasgow to Belfast route. Cross channel steam services were inaugurated in 1821 and longer-distance coastal services followed in rapid succession e.g. in 1822 the James Watt between Leith and London followed by the United Kingdom on the same route in 1826. Apart from passengers typical cargo might be salmon from Scotland and beer back. These developments were seen as such a success that even their Lordships at the Admiralty could not avoid drawing the inevitable conclusion that there was more to steam than hot air and commissioned the first Royal Navy steam ship, another Comet launched in 1822 but not entered on the Navy list till 1831. The more influential H.M.S. Lightning was launched in 1823 and remained in service for fifty years.
In spite of these advances in steam, there was considerable opposition to its use, and not just from sailors. Steam engines had an unpleasant characteristic; they converted the boats in which they were fitted into potential floating bombs. In America, where far greater numbers of these vessels were used than in the U.K., between 1816 and 1848 no fewer than 233 exploded. Sail was still seen as an attractive alternative! In spite of the urgent need for more reliable and quicker communication between Britain and her increasingly far-flung empire, a request for the introduction of a steamer to carry mails from Malta to Corfu was rejected by Lord Melville, then First Lord of the Admiralty, because they “felt it their bounden duty, upon national and professional ground, to discourage to the utmost of their ability, the employment of steam vessels, as they considered that the introduction of steam was calculated to strike a fatal blow to the naval Supremacy of the Empire...thin end of the wedge...lead to similar demands...other departments.” Such thinking evidently goes with the turf. However, it was good for sail as it meant that in 1830 sailing ships in Britain still outnumbered steam ships by seventy to one.
Steam propulsion did not really take off in shipping until the development of efficient compound engines in the 1860s. Thereafter its dominance was rapidly established and by 1900, precisely the time at which Dum finished his apprenticeship, the commercial sailing ship was essentially obsolete, even though they continued in use in some countries as late as the 1950s. However, the U.K. was one of the first nations to embrace the new steam technology wholeheartedly, and disposed of its sailing fleet early. Likewise, having served his time as an apprentice under sail, all the rest of Dum's ‘sailing’ was in steamers.
The progress of steam was not smooth and linear; there was retrograde movement as in that of the Archimedes, a propeller driven steamer launched in about 1836 which, after defeating the paddle steamer H.M.S. Widgeon in a race in 1839, blew up her boiler, broke a crankshaft and ran ashore off Beachy Head all within a year for which she was punished by conversion into a sailing ship. Another example was the three iron ships the Bosphorus, the Hellespont and the Propontis which the General Screw Steam Shipping Co. specifically had built for taking emigrants to Australia. The venture failed so spectacularly that after the Government took on the ships they, too, were converted into sailers as late as the 1850s. Nor did sail give up without a struggle. Conrad wrote of the occasion on which the full rigged ship the Tweed in the 1860s beat the steam mail boat from Hong Kong to Singapore by a day and a half. This was exceptional even at the time and such victories became increasingly scarce. The Tweed moreover was an exceptional ship; imitation being the sincerest form of flattery, it is worth noting that the famous tea clippers Cutty Sark, Blackadder and Hallowe'en were all more or less modelled on the Tweed and all three were rated outstanding vessels in their day. Oustanding was generally synonymous with fast; fast ships tended to be wetter than slow ones. Nobody minded about that - apart from the men!
Among the most pressing Imperial needs for faster transport was India. Round the Cape was slow - 120 to 180 days; via Suez, not the canal which did not open till 1869, but the Overland Route, was unreliable, expensive, unhealthy [plague, among other things, being endemic], not much quicker, and in any case not fully developed till after about 1830. The Overland Route had been used since ‘time immemorial’. Dhows between India and the Red Sea usually put in at Cosseir, as the prevailing winds made access further up the Suez impossible. From Cosseir people and goods went aboard camels and donkeys across the desert before boarding ship again on the Nile near Luxor and thence down to Cairo, Alexandria and the Mediterranean. This was not a journey for the faint-hearted. The introduction of steamers on some sections of the Nile shortened the time somewhat but brought no other solace. The introduction around 1838 of a flat-bottomed steamer called the Cairo considerably improved the overall time for the 250 mile trip from Alexandria to Suez to 78 hours including a 12 hour break in Cairo.
Demand for this route became so great by the early 1840s that as many as 4,000 camels would be needed to convey one ship's complement of passengers and cargo, but it was still a costly transit and of necessity only justified transporting valuable and lightish commodities. By 1868, the year before the canal opened, the volume of trade via the Overland Route amounted to some £40 million a year, whereas P. & O. steamer traffic to the Eastern ports was put at some £110 million. The first attempt to establish an Indian service was in 1821 with a wooden paddle steamer, the Enterprise but taking 103 days from London to Calcutta condemned her thereafter to the ignominy of postal work between Calcutta and Burma. A good time under sail in the late 19th century from London to Calcutta was 80 days. A reasonable time was 90-95 days. 103 days was deemed unreasonable.