At Portsmouth the tide flows about seven hours and ebbs about five; and the velocity with which the ebb tide runs out effectually scours the channel at the mouth of the harbour, and prevents the accumulation of sand. It is high water in the harbour at half-past 11 o'clock at the full and change of the moon; and the rise of spring tides is about eighteen feet, and of neaps about twelve. In the months of March and April the specific gravity of the water in Portsmouth harbour becomes so much increased, that ships lying there are observed to float about two inches lighter than at other times of the year. The latitude of the Observatory in the Dock-yard is 50° 48' 3" north; longitude 1° 5' 59" west.
Though Portsmouth does not appear to have been a place of much consideration as a naval station previous to the reign of Henry VIII., who may be regarded as the first English King that established a permanent royal navy, it was yet undoubtedly a town of some consequence long before that time. In 1194, Richard I. granted a charter to the inhabitants, wherein, after declaring that he retains the town of "Portsmue" in his own hands, he establishes an annual fair to be held therein for fifteen days, to which all persons of England, Normandy, Poictou, Wales, Scotland, and all others, either foreigners or his own people, might freely resort, and enjoy the same privileges as at the fairs of Winchester, Hoiland, or elsewhere in his dominions. The burgesses of "Portsmue," as the place was then called, were also allowed to have a weekly market, with the same privileges and immunities as those of Winchester and Oxford; with freedom from all tolls of portage, passage, and stallage, and exemption from suit and service at hundred and county courts.[9] This charter was confirmed in 1201 by King John, and in 1230 by Henry II.; and in 1256 the latter monarch granted another charter, establishing a guild of merchants at Portsmouth. The privileges of the burgesses were at several different times confirmed by succeeding kings; and, in 1627, Charles I. granted them a charter, whereby a mayor and twelve aldermen were appointed for the civil government of the town. This charter, which was renewed by Charles II., has since been modified by the Municipal Reform Bill of 1835, which directs that the borough shall be divided into six wards, which shall elect a town council of forty-two members. In 1298 the borough was summoned to send two members to Parliament, a privilege which it continues to enjoy.
PORTSMOUTH.
RIGGING-HULK, WITH A NEW FRIGATE ALONGSIDE.
In this engraving we have a view of a new frigate, with only her lower masts in, lying alongside of the Topaze rigging-hulk. The latter vessel—which now presents so clumsy an appearance, from her bows and sides being sheathed with a stout doubling of timber, and from a wooden house being built over her stem—was formerly a French frigate, and, when she first came into our possession, she was much admired by nautical men for the beauty of her build. Further in the distance, to the right, is seen a first-rate lying off the Dockyard Quay, partly rigged; and, beyond her, are perceived the immense wooden roofs which cover the building-slips. The line of building to the right is the rigging-house, and the tower erected above it is the Dockyard Semaphore. On the extreme right, towards the front, is seen the forepart of a mooring-lighter, with one of the numerous spar-booms lying afloat near the Common Hard. The original picture was exhibited in the Gallery of the British Institution, where it excited general admiration.
The great naval depôt at Portsmouth is partially described in connection with other engravings in this work, and we have therefore thought it might be interesting to occupy our present space with some details respecting the peculiar mode in which one very important portion of the rigging is manufactured in this yard, and which forms a principal object of curiosity to all persons visiting it. We allude to the machinery for manufacturing blocks, invented by Mr. Brunel, the celebrated engineer.
After the wood—generally elm—for the shell of the block is cut into proper sizes by circular-saws, its complete formation, including the pin and the sheave, is effected by means of several different machines, all contrived with the greatest mechanical skill, and put in motion by a steam-engine. The first process is that of the boring-machine, which, by means of a centre-bit, pierces a hole to receive the pin, and at the same time, according as the block is intended to be single or double, forms one or two similar holes, at right angles to the former, to receive the first stroke of the chisel which cuts out the space for the sheave. By the second, called the mortising-machine, this space is cut out by a chisel acting vertically, and making about a hundred and twenty strokes a minute, and under which the block is caused to move gradually, so that at each stroke a thin piece of the wood is cut away. After this the block is taken to a circular-saw, which cuts off the corners, and reduces it to the form of an octagon. The shaping-machine, to which it is next taken, consists of two equal and parallel wheels moving on the same axis, to which one of them is permanently fixed, while the other is moveable in the line of the axis, so that, by sliding it nearer to the former, or more apart, as may be required, the shells of blocks of all sizes may be fixed between their two parallel rims. Ten shells of the same size being firmly fixed at regular intervals between those rims, the wheels are put into motion with extreme velocity, and the shells are rounded by striking against a cutting instrument, which at the same time moves in such a manner as to give to each block its proper shape and curvature. When one half of the side has thus been finished, the motion of the wheels is reversed, and the other half finished in the same manner. When one side has been rounded, the shells are reversed, and the other side completed as above. The last process which the shell undergoes consists in scooping out the groove for the strap, or "strop," as the rope is called, which goes round the block. The shell is now completed, and the visitor is next shown the different processes in forming the sheave and the pin.