Then 25491.67594271.188 tons, the burthen or tonnage required.

2. The length from the back of the stern-post to a line let fall from the fore-part of the main-stem, is 108 feet 9 inches; the extreme breadth from outside to outside of the plank, 29 feet 6 inches; required the tonnage of the vessel.

Ans. 421.469 tons.

CASE II.

When the vessel is afloat.

RULE.

Let fall a plumb-line over the stern of the ship, and measure the distance between this line and the aft-part of the stern-post, at the load water-mark; then measure from the top of the said plumb-line, in a parallel direction with the water, to a perpendicular point immediately over the load water-mark, at the fore-part of the main-stem; from the last measured distance subtract the former; and the remainder will be the ship's extreme length. From this length, deduct 3 inches for every foot of load-draught of water, for the rake abaft; and also of the ship's extreme breadth, for the rake of the stem; and the remainder will be the true length of the keel, for tonnage. The extreme breadth inust be measured, and the tonnage found as directed in the first Case.

EXAMPLE.

The true length of an eighty-gun ship, after all deductions are made, in taking the dimensions, is 150

feet 9 inches; and the extreme breadth 50 feet 6 inches; required the tonnage of the vessel.

Ans. 2044.9478 tons.

Note 1.-It is found by experience, that ships of war carry less; and most merchant-ships carry considerably more tonnage than they are rated at, by the preceding Rules.'

2. Some Writers on this subject, divide by 100, instead of 94, for King's ships. On the same principles, the divisors for Merchants' ships should be decreased, perhaps to 90 or 92.

3. Solutions to the last two Questions, may be found in the Key to Nesbit's and Little's Practical Gauging.

ABACUS. A square table, list, or plinth, in the upper part of the chapiters of columns, especially those of the Corinthian order.

ABREVOIRS. The seams or joints between stones and bricks, in laying them.

ACANTHUS. The herb whose leaves are represented in the capital of the Corinthian column.

ACROTERS. Sharp and spiry battlements or pinnacles, that stand in ranges, with rails and balusters, upon flat buildings. Also pedestals upon the corners and middle of pediments, to support statues.

ALCOVE. A recess in a room for a bed of state; also an arched building in a garden or pleasure-ground. AMPHITHEATRE. An edifice of an oval or circular form, with rows of seats rising one above another, in order to accommodate the people who attend in it, to see public diversions.

ANTICHAMBER. The room that leads to the chief apartment; also a room in a nobleman's house, in which strangers stay till the party to be spoken with is at leisure.

AQUEDUCT. A construction of timber or stone, made on uneven ground to preserve the level of the water,

and convey it, as by a canal, from one place to another.

The Romans were extremely sumptuous and magnificent in their Aqueducts, some of which extended 100 miles. Frontinus and Blasius inform us that the city of Rome was supplied with 500,000 hogsheads of water every twenty-four hours, from nine Aqueducts, which emptied themselves through 13,514 pipes of an inch in diameter.

ARCH. A curved line; a vault. See page 238. ARCHITECT. A person who professes the science of Architecture; and whose business it is, if required, to give draughts or designs of intended buildings, with estimates of the expenses necessary to complete them; to superintend the workmen, and to give directions concerning the manner and method of executing the whole.

ARCHITECTURE. The science which teaches the method of building, being a skill obtained by the art of designing, aided by the precepts of Geometry. By it, Rules are given for planning and raising all sorts of structures, according to Geometry and proportion. The scheme or projection of a building is easily laid down in three several draughts or designs. The first is a plan, which exhibits the extent, division, and distribution of the ground into apartments, and other conveniences. The second shews the heights of the different stories, and the outward appearance of the whole building; and is called the design or elevation. The third, called the section or profile, shews the inside of each apartment.

From these three draughts or designs, the Architect or Undertaker makes a computation of the probable expense of the building, and the time required to complete it.

ARCHITRAVE. The moulding or ornament immediately above the capital of a column; it being always the next member below the frieze. Also the chief or principal beam of a building.

M m

Doors and windows which have architraves on the jambs, and over the cap-pieces, are also denominated architrave-doors and architrave-windows.

ASHLAR. Free-stone, as it comes rough out of the quarry, before it receives form and shape from the tool of the Stone-cutter.

ASHLERING. Quartering in garrets, from the floor to the under side of the rafter It is generally perpendi

cular to the floor; and 2 or 3 feet in height. ASTRAGAL. A little round moulding in the form of a ring, serving as an ornament at the top or bottom of a column. The shaft of a column always terminates at the top with an astragal, and at the bottom with a fillet. ATTIC. A little order, placed above another much greater; for instead of pillars, this order has nothing but pilasters with a cornice architraved, for an entablement. This order is sometimes used in conjunction with the Ionic and Doric orders.

The word is also used to denote the uppermost part of a building, or the highest story.

B.

BALCONY. A projection beyond the naked front of a wall or building, supported by pillars, and encompassed with a balustrade. Also a kind of open gallery. BALK. A large piece of timber.

BALUSTRADE. A term used to signify a row of turned pillars, called balusters, made of marble, iron, wood, or stone, with a hand-rail upon the top; and fixed upon a terrace, the top of a building, a balcony, a stair-case, &c. &c.

BAND. Any flat member that is broad, but not very deep. A list, a fillet.

BARGE-COURSE. A term used for that part of the tiling which projects over the gable-end of a building. BASE. A rest, a support, a foundation; the bottom of any thing. It is used to signify any body which bears up another; but it is particularly applied to the bottoms of columns and pedestals.