India pale ale elsewhere. Previously, Englishmen had drunk mainly stout and porter, but bitter (a development of pale ale) came to predominate. Beers from Burton were considered of a particularly high quality due to synergy between the malt and hops in use and local water chemistry, especially the presence of gypsum. This extensively hopped, lighter beer was easier to store and transport, and so favoured the growth of larger breweries. The switch from pewter tankards to glassware also led drinkers to prefer lighter beers. The development of rail links to Liverpool enabled brewers to export their beer throughout the British Empire. Burton retained absolute dominance in pale ale brewing: at its height one quarter of all beer sold in Britain was produced there until a chemist, C. W. Vincent discovered the process of Burtonisation to reproduce the chemical composition of the water from Burton-upon-Trent, thus giving any brewery the capability to brew pale ale. In 1880, prime minister William Gladstone's government used the Inland Revenue Act 1880 to replace the long-standing malt tax with a duty on the finished product – beer. As a side effect, homebrewers that produced their own beer for "domestic use" were subject to registration, regulation and inspection, and were required to pay a licence fee. Home brewing was greatly reduced. In the 19th century, a typical brewery produced three or four mild ales, usually designated by a number of Xs, the weakest being X, the strongest XXXX. They were considerably stronger than the milds of today, with the gravity ranging from around 1.055 to 1.072 (about 5.5% to 7% ABV). Gravities dropped throughout the late 19th century and by 1914 the weakest milds were down to about 1.045, still considerably stronger than modern versions. Continental lagers began to be offered in pubs in the late 19th century, but remained a small part of the market for many decades. 1900 to 1949: Temperance and war The temperance movement of the late 19th and early 20th centuries, in combination with First World War emergency measures, introduced a number of changes, such as higher taxation on beer, lower strengths, a ban on "buying a round" and restricted opening hours. Most were gradually repealed over subsequent decades. The First World War measures had a particularly dramatic effect upon mild ale. As the biggest-selling beer, it suffered the largest cut in gravity when breweries had to limit the average original