first beer to be aged at the brewery and despatched in a condition fit to be drunk immediately. It was the first beer that could be made on any large scale, and the London porter brewers, such as Whitbread, Truman, Parsons and Thrale, achieved great success financially. The large London porter breweries pioneered many technological advances, such as the construction of large storage vats, the use of the thermometer (about 1760), the hydrometer (1770), and attemperators (about 1780). The 18th century also saw the development of India pale ale. Among the earliest known named brewers whose beers were exported to India was George Hodgson of the Bow Brewery, The late 18th century saw a system of progressive taxation based on the strength of beer in terms of cost of ingredients, leading to three distinct gradations: "table", "small" and "strong" beer. Mixing these types was used as a way of achieving variation, and sometimes avoiding taxation, and remained popular for more than a century afterwards. The beer engine (a simple lift-pump), a device for manually pumping beer from a container in a pub's basement or cellar, was invented by Joseph Bramah in 1797. The bar-mounted pump handle, with its changeable pump clip indicating the beer on offer remains a familiar and characteristic sight in most English pubs. Before the beer engine, beer was generally poured into jugs in the cellar or tap room and carried into the serving area. The Beerhouse Act 1830 enabled anyone to brew and sell beer, ale or cider, whether from a public house or their own homes, upon obtaining a moderately priced licence of just under £2 for beer and ale and £1 for cider, without recourse to obtaining them from justices of the peace, as was previously required. The result was the opening of hundreds of new pubs throughout England, and the reduction of the influence of the large breweries. One of the motivations of the Act was to reduce the abusive over-consumption of gin. Demand for the export style of pale ale, which had become known as "India pale ale" (IPA), developed in England around 1840. IPA became a popular product in England. Some brewers dropped the term "India" in the late 19th century, but records indicated that these "pale ales" retained the features of earlier IPA. A pale and well-hopped style of beer was developed in Burton-on-Trent in parallel with the development of