Tom Tower

Tom Tower stands over Tom Gate on St Aldates, the main entrance to Christ Church in Oxford. Designed by Christopher Wren and built in 1681–82, it crowns the gatehouse left unfinished by Cardinal Wolsey after his fall in 1529. The tower’s octagonal lantern and facetted ogee dome were deliberately Gothic, a style Wren argued should match the Founder’s work. Christopher Kempster of Burford, the stonemason Wren recommended, supervised the building since Wren never visited Oxford. The tower later inspired William Kent’s dome at Hampton Court and a Harvard tower at Dunster House. Great Tom, the bell housed inside, weighs six and a quarter tons and was moved from Osney Abbey after the Dissolution. It has rung every night since the Second World War, sounding 101 times to mark the original 100 scholars plus one added in 1663. The bell was recast several times, finally in 1680 by Christopher Hodson, and bears a Latin inscription thanking Henry Smith and Hodson. It is rung at 21:05 UK time, once marking Oxford’s local mean time when noon there lagged five minutes behind Greenwich. The bell is only swung on special occasions and has inspired Morris tunes and rounds like “Old Tom of Oxford.” The tower’s clock mechanism, installed in 1889 by J. B. Joyce & Co, uses a double three-legged gravity escapement invented by Lord Grimthorpe. Its striking train has a 24-inch main wheel and a 300-pound hammer, while the pendulum beats every one and a half seconds. The pendulum itself is made of zinc and iron to resist temperature changes. From the tower’s base, visitors step into Tom Quad, the largest quadrangle in Oxford, framed by buildings that include the hall where Alice in Wonderland first appeared.