A steam boiler like this one, made in the late 18th century, is often called a colonial boiler. Steam boilers were used in factories throughout Australia, mounted over similar designs of brick furnaces. This boiler is a fire tube type, in which the heat from the fire travels through the tubes and water circulates around them. Another kind of boiler is a water tube boiler, in which the water is inside the tubes and the heat of the combustion surrounds the tubes. The boiler in our collection burned wood as fuel but others of this design could also burn coal, coke, gas and liquid fuels. The boiler was made by T & F Johnson, boilermakers. In 1922 their factory was located at Coventry Street, South Melbourne. They were still advertising their 'Colonial, multi, vertical boilers, all sizes' at the same address in 1934. The connected pressure gauge, made in London by Dewrance, measures 0 to 400 pounds per square inch. John Dewrance is renowned as a pioneer of the steam locomotive in the early 19th century. He founded John Dewrance & Co. in South London in 1844. His son Sir John Dewrance took over in 1879. In 1939 the company became a subsidiary of Babcock & Wilcox, and was eventually owned by Emerson. How the boiler works: - A boiler is about two-thirds filled with water and heat is applied, in this case in the form of burning wood. The heat is transferred through the metal of the boiler to the water. When the water boils the steam rises to the top, and as it escapes from the boiler the steam pressure builds up in the steam space to later be released to do work; drive machinery such as ship and train engines, turbines, presses, wheels, and driving belts to operate looms and saws. The heat associated with the boiler can be used for preserving food, sterilising, factory manufacturing processes, and steaming wood for shipbuildin. Every boiler has several components fitted for safe operation: - - Safety valves - Gauge glass - Pressure gauge - Main steam stop valve - Water check valve - Blowdown valve - Manhole doorThe boiler is a significant item that gives us a snapshot of early Melbourne's industrial history. It is an example of the technological advancement during the Industrial Revolution where steam-driven machinery and motors could perform tasks more efficiently than manual labour. The makers were one of many boilermaker businesses in Melbourne during the early late-19th andearly 20th centuries. The maritime trade and skills of boilermaking are still learned and applied today. The Dewrance steam pressure gauge connected to the boiler was made by the London firms foundered by John Dewrance. He was renowned for developing the steam locomotive in the early 19th century.Boiler; a horizontal cylindrical underfired steam boiler. It is a multi-tubular design and is timber plank-clad, with brass fittings and pressure gauges. The boiler has an iron door at one end with a metal chimney above it. It is installed over a brick-enclosed solid fuel furnace. Two large, wood-mounted pressure gauges are connected to the boiler and have inscriptions. An inscription is on a red, cast iron plaque above the boiler door. The boiler's maker is T & F Johnson, South Melbourne. One of the pressure gauges was made by Dewrance, London..Maker's plate: "T & F JOHNSON / BOILERMAKERS / SOUTH MELBOURNE" Pressure gauge: "POUNDS PRESSURE / PER [square] INCH / DEWRANCE LONDON"flagstaff hill, warrnambool, maritime museum, shipwreck coast, flagstaff hill maritime village, great ocean road, boiler, multi tube boiler, steam boiler, steam technology, underfired boiler, horizontal boiler, timber clad boiler, steam power, industrialisation, boilermakers, south melbourne, dewrance, john dewrance, pressure gauge, dewrance pressure gauge, t & f johnson, london, steam engine, steam locomotive, pounds per square inch, 19th century, steam machine