“The manner in which these quarries are worked is the following. On the galleries, or terraces, large masses of slate are first detached by means of powder, and then roughly hewn into shape. There are laid along each of these terraces tram-roads formed of rails loosely laid down, upon which the masses of slate, in waggons with suitable wheels, are thrust along by men to the little houses situated on the declivity of the mountain, at the extremities of the galleries. Here they are split into smaller plates; and it is curious to observe how regularly the slate splits into fine and still finer plates, down to the thickness of three or four lines. Several pieces are allowed to retain a thickness of an inch or an inch and a half, and are used for tables and flagstones, the thinner ones for covering roofs, &c. The manner, too, in which they are squared, being cut out at once by a sort of hatchet, according to a line made by means of a ruler, is very curious. The plates thus formed are distinguished by very amusing names. Thus the largest are called _queens_, the next _princesses_, then _duchesses_, _ladies_, and so on. The enormous quantity of slate produced may be estimated from the facts, that a railway has been constructed specially from these quarries to Penrhyn harbour, at an expense of £170,000, which _every week_ takes down between 500 and 600 tons, or about 12,000 cwt. of slate; and that the yearly net produce has sometimes brought in as much as £60,000 to the owner of the quarry, the Hon. Douglas Pennant.
“The quarrying itself is attended with considerable danger. The workmen, when a portion of the rock is to be blasted from the upper part of a gallery, are obliged to bore the hole, suspended in mid-air by ropes, to load the hole so bored, to set fire to the match, and then to place themselves beyond the reach of the explosion. They are also exposed to the chance of accidents from the falling of portions of the sharp slate; and it was carious, even yesterday—on which, being pay-day, the work was not regularly going on—to hear now and then the explosion of the blasting of some part of the rock, at the same time that it was almost difficult to pass along the galleries, without falling over the little railways or some of the sharp pieces of stone. The manner in which Queen Victoria was received here, on her visit some years ago, must have produced a curious effect. As soon as she arrived, 1300 explosions were heard from all parts of the quarry, having been all previously prepared for this purpose. After having (the greater part of the time in the rain) inspected all the parts of this immense quarry, and, besides, a saw-mill, for cutting up the thicker plates of the slate, we returned towards Bangor, and visited Penrhyn Castle, the property of the Hon. D. Pennant. In olden times, a castle belonging to Roderic Molwynog, grandson of Cadwallader, stood on this spot. It was rebuilt in the time of Henry the Sixth, and has been quite lately renewed (under the direction of a London architect, of the name of Hopper) by the father-in-law of the present possessor. It is a remarkable and splendid building, such as could only be completed with a revenue like that proceeding from the quarries.