On Thursday (last week) a fire broke out in the town of Watford, which reduced to a heap of ruins the old building used as the Corn Exchange and Market-house. On the alarm being given, it was recollected that about 23 years since every house opposite the premises on fire was destroyed by a similar misfortune; and the Market-house was then partially destroyed. The authorities, fearing the recurrence of a like calamity, and profiting by the proximity to the London and North-Western Railway, sent an electric telegraph message to London for the aid of the Fire Brigade engines. Two engines were, by the order of Mr. Braidwood, the superintendent, dispatched to Euston-square, for the purpose of proceeding by a special train to the scene of the conflagration.

Notwithstanding this precaution, at noon next day the ruins were still emitting sheets of fire, and some hours elapsed before the fire was wholly extinguished. The damage done may thus be described.

The Market-house burnt down; the contents, consisting of 90 quarters of wheat, 100 quarters of oats, and a considerable quantity of barley, and other produce, destroyed.

The premises of Mrs. Taylor, the King's Head Hotel, much damaged by fire and water.

The Spread Eagle Hotel, kept by Mr. Coulson, had the windows demolished and the shutters burnt.

The premises of Mr. Hollingsworth, a butcher, were also much burnt; as were those belonging to Mr. Blunt, also a butcher.

Mr Flaxman, a corn-dealer, and Mr. Tizen, are likewise considerable losers.

The origin of the fire is not precisely known, but there is strong ground for supposing that it was the work of incendiarism.

The illustration upon the next page, sketched by Mr. Hanshew from a window of the King's Head Hotel, shows the Market-house, a low-pitched building of considerable age, now a mass of black ruins.