For hundreds of years, people have played about with steam toys. Around AD 100, Hero of Alexandria described the ‘Aeolipyle’, a primitive form of reaction turbine. Then the Greeks arranged that, in their temples, doors should open suddenly to reveal the god after the worshipper had lit a fire on the altar. The fire heated water in a closed ‘boiler’ so that, when it boiled, it was forced through a pipe into a bucket, rather like the present day ‘Teasmade’. The extra weight in the bucket caused it to drop and so open the doors.

The first attempts

After 1600, there was renewed interest in the properties of steam but, at first, this was mainly an intellectual pursuit. We can trace two lines of development, one in which the pressure of the steam was applied against the surface of water to force that water up a pipe, and the other in which the steam pushed against a piston. Salomon de Caus came to England around 1609 and was involved in designing gardens at Hatfield House and Greenwich Palace where fountains were laid out. One idea he published for creating fountains was to fill a copper sphere with water and to heat it. A pipe with a control valve reached nearly to the bottom of the sphere so that, when steam pressure rose inside, water would be squirted out of the pipe. There do not appear to have been any safety valves, water level indicators or other safety features which we would consider necessary today.

In 1834, on the occasion of an appeal for a memorial to Watt which would be erected in Westminster Abbey, the effect of his steam engine was summed up in the following words:

Right at the end of the reciprocating steam engine era appeared one based on different principles from earlier designs which enabled it to compete for a while not only with the steam turbine but also the diesel. In fact development work on it continued in the United States of America right up to the 1940s. It was called the ‘Uniflow’, or on the Continent and United States ‘Unaflow’, through the way in which the steam was used in the cylinder. Normally this type was double-acting with only inlet valves fitted at either end of the cylinder. The steam was exhausted through a central ring of ports in the middle of the cylinder which were closed by the movement of the piston. The piston had to be made almost as long as the length of the stroke, about 10 per cent less was customary. The steam entered at one end of the cylinder and pushed the piston along. Most of it escaped through the exhaust ports and what was left was compressed as the piston returned, raising its temperature. The attractive feature of the Uniflow engine was the good thermodynamic layout because the inlet end always remained hot and the centre with the exhaust stayed cold. The residual steam was reheated by the compression back to the temperature of the incoming steam so there was no heat loss through condensation.

The person who originated the vital inventions and discoveries for making the first successful rotative engine was James Watt, born at Greenock on the Firth of Clyde in 1736. His paternal grandfather had been a teacher of navigational mathematics while his father and uncle were practised surveyors. In addition, his father's business included marine engineering. On his mother's side, he was related to George Muirhead, a professor of Classics at Glasgow University. With such a background, it was only natural that Watt's interests would lie in similar areas. No one could have imagined that, when Professor James Anderson asked Watt to repair a model of an atmospheric engine belonging to the Natural Philosophy class of the College of Glasgow University during the 1763–4 session, it would be a turning point in the history of civilisation. Watt found that the boiler, although correct in scale, could not supply enough steam to work the model for more than a few strokes. Through his experiments, he found that, at every stroke, the quantity of steam consumed was several times greater than the volume of the cylinder. He also discovered that a great deal more water was needed to condense the steam than he reckoned ought to be necessary if the laws of proportions for mixing liquids of different temperatures applied.

It had long been known that much steam was wasted in atmospheric engines through the heating and cooling of the cylinder at every stroke.

Immediately after the First World War, the cotton textile industry entered a period of boom as manufacturers tried to catch up on orders that had been delayed by that war. However this was short-lived because some countries to which Britain had been accustomed to export cloth had developed their own capacity for spinning and weaving. In Lancashire, some mills in the course of construction when the war started, like the Ace Mill at Chadderton, were completed when it finished. But then others which it was intended should be doubled like the Hare Mill (renamed Mons after the war) at Todmorden, and the Pear Mill, Stockport, never had the second section added. The last three traditional style Lancashire cotton spinning mills were finished in 1926 and 1927 and each was driven in a different way.

For the Wye Mill Co.'s No. 2 Mill, Shaw, Buckley & Taylor built their largest and last engine in the traditional style with 50 ropes round a 24 ft diam. flywheel weighing 90 tons driving the shafting. It was a cross compound designed to develop 2,500 h.p. with cylinders 32 and 70 in bore by 5 ft stroke. The speed was a stately 66 r.p.m. The parts were massive to take such power at such a slow speed with the enormous single slipper crossheads. Even these huge castings proved to be inadequate when the foundations at the back of the lowpressure cylinder settled and the crosshead guides cracked.

Around 1850, the compound engine, which was suitable for higher steam pressures, had been introduced based on Woolf's principles but had not been widely accepted in the textile areas. The Lancashire boiler was gaining in popularity and this again was suitable for higher pressures. In spite of the various pointers to more efficient and economical steam engines, the Lancashire textile millowners continued to prefer the low-pressure beam engine either in its single-cylinder form or with pairs of engines throughout the period up to the 1860s. Such engines were regarded as safer because less damage occurred if there were boiler explosions and their reliability had been proved. Also until about 1850, there was no theoretical reason to consider that an engine using higher pressures would give greater economy and that therefore there could be advantages in adopting high-pressure steam.

It is interesting to note where high-pressure steam was introduced first. It was in cases where a high starting torque was essential. The textile mill engine never started to drive the whole mill at the beginning of the day because, at night just before the mill was due to stop running, a whistle was sounded and the operatives disengaged their machines.

Looking today at the massive scale and crudity of early atmospheric engines, we find it hard to imagine that Newcomen was working at the limits of engineering technology available to him. The cylinders in particular were difficult to bore accurately, a problem which remained for many years. An account for the construction of an atmospheric engine in 1727 for Edmonstone Colliery in Midlothian shows that the cylinder alone cost £250 out of £1,007 for the engine which did not include the cost of building the enginehouse nor the labour charges of the engine erectors.

The bucket pumps fitted to atmospheric engines were more suitable for raising a little water a great height rather than a large quantity of water a small distance. Then, the smaller engines did not work as well and were more expensive to run in proportion to larger ones which in any case consumed so much fuel that they were economic only either where fuel was cheap or where the product was very valuable. In the Cornish mines, the value of the ore had to pay for the expense of bringing from South Wales coal which happened to have a high calorific content. At this period, coal was transported in large lumps so that smaller pieces were regarded as waste and it was this waste which supplied the boilers of the engines pumping dry the coal mines.

So wrote Fairbairn in 1861. He had good reason to value the importance of boilers. He had built many steam engines and carried out experiments to improve their efficiency. He had also experimented with different types of boilers and tried various ways of burning coal in their furnaces as efficiently as possible, with the result that he developed the ‘Lancashire’ boiler, which was the most usual type in cotton mills from roughly the 1850s until the final abandonment of steam power.

Yet boilers have been too often the forgotten and most neglected parts of steam engines, with sometimes literally fatal results. This was because most people lacked even a basic understanding about how they should function. First, it was necessary to learn about the nature of coal and the different properties of the various types. Then the furnace had to be designed to burn the particular coal in the best way.

The increasing boiler pressures, the increasing speed of engines, the need for more accurate control of the speed and the development of compounding all meant that the older forms of valve gear became increasingly inadequate. Once it was seen that it was necessary to allow the steam to expand in the cylinder as much as possible, and therefore utilise the maximum range of heat, there was a gradual change from controlling the speed and power of the engine with the throttle valve to devising ways of allowing the steam to enter the cylinder at maximum pressure and then cutting off the entry of the steam at a suitable point to allow it to expand before the exhaust valve opened. The ideal valve should open quickly to allow the maximum amount of steam to enter the cylinder at maximum available pressure, e.g. full boiler pressure, for the precise period of time necessary to generate sufficient power to drive the engine and then it should close quickly, leaving the steam to expand until the end of the stroke. The exhaust valve too had to open quickly to allow the steam to pass to the condenser as quickly as possible, ideally at the same pressure as the condenser. The exhaust valve should remain open for the duration of the exhaust stroke to keep any back pressure low until it closed before the piston actually reached the end of the cylinder to create some compression to act as a cushion.

The Boulton & Watt rotative engine made a dramatic impact on the standard of civilisation and was one of the crucial machines which helped to launch the Industrial Revolution. This engine became the standard design for providing rotative power everywhere, even for a short period on board ships. It was a design which other manufacturers found they had to copy or else face failure. Some tried other types, but

Even the Watt engine needed many years of trials and modifications before it became the paragon and envy of everybody.

The total number of engines built by the Boulton & Watt partnership up to 1800 was 496, of which 38 per cent were pumping and 62 per cent rotative, mostly for the textile industry. There were 164 pumping engines, 24 blowing engines and 308 engines driving machinery.

The development by Joseph Swan and Thomas Edison in 1879 of the incandescent electric light bulb was to have far reaching effects because it launched the electricity supply industry. Up to that time, generators were used in plating works which did not need much power. There were arc lights but while these illuminated large spaces such as railway stations, they were too bright and unsuitable for small rooms in offices or domestic houses. The incandescent light bulb did not give off the fumes or heat of gas lights or candles and the energy needed to power them could be transmitted comparatively easily through wiring. The electric motor followed and created new demands for electrical power, particularly with the development of transport systems on both railways and tramways. Magnus Volk opened his small railway on the front of Brighton on 4 August 1883, but development was slow elsewhere for some years. Electricity had many advantages over older forms of power distribution. Compared with line-shafting, it could be distributed over longer distances and to less accessible places. As long as line-shafting was running, there were frictional losses in the bearings but, although electricity had to be constantly available, distribution losses were not apparent to the domestic consumer.