What is a line?

A. A line is formed by the motion of a point; and therefore in one dimension only, i. e. length. How is a superficies generated?

A By the motion of a line, and so hath two dimensions, i. e. length and breadth. Q. How is a solid produced?

A. By the motion of a superficies, and hath three dimensions, length, breadth and thickness. Q. How is geometry divided?

A. Into three principal parts.

I. Altimetry, which is applied to the measuring of all heights, accessible or inaccessible.

H. Planimetry, which teaches the mensuration of surfaces in square measures, such as square miles, yards, feet, inches, &c.

III. Stereometry, which is the mensuration of all kinds of solid bodies in solid, or cubic measures, as cubic feet, cubic inches, &c. This also includes gauging, or the art of finding the contents of any cask or vessel, or the quantity of liquid contained in them; also timber measure, superficial and solid.

LESSON XH.

ARCHITECTURE.

WHAT is architecture?

A. The art of building or raising all kinds of edifices; as houses, churches, palaces, &c.

How is architecture distinguished?

A. Into three sorts, civil, military and naval.
Q. In what consists civil architecture?

A. In external ornaments and internal con-
veniencies.
Q. What

What are the orders of civil architecture? A. They are generally reckoned five. First, the Tuscan; Second, the Doric; Third, the Ionic; Fourth, the Corinthian; Fifth, the Composite.

To these may be added the Gothic, which is an old method of building, still preserved in the construction of almost all cathedral churches. These orders take their names from the people who invented them.

Q. What are the qualifications necessary for a good architect?

A. He ought to understand drawing, geometry, optics, arithmetic, history, and fable Q. In what consists military architecture, called fortification?

A. In constructing such works about a town, &c. as will enable a small number of men within, to withstand, for a considerable time, the assaults of a greater number without. A town fortified is called a fortress.

Q. What is naval architecture?

A. The art of constructing vessels, whether for the service of war or commerce.

PAINTING.

What is painting?

A. An art, teaching by drawing and the application of colors, to represent all sorts of ob jects.

Q. What are the most esteemed paintings? A. Those representing historical events. Q. How many sorts of painting are there? A. Five. First, in Oil. Second, in Fresco. Third, in Water-colors. Fourth, on Glass, and Fifth, in Enamel.

To

To which may be added miniature and pastel. Painting in oil was unknown to the ancients. This art has received the greatest advantage from this discovery.

Q. What are the qualifications of an excellent painter ?

A. He ought to understand drawing in its highest perfection. He ought to have some knowledge of anatomy and geometry. He ought. to read a great deal, to have great judgment and patience he ought to be sober and fond of his art.

SCULPTURE.

What is sculpture ?

A. The art of carving, or hewing stone inte images. Every thing that is engraved or worked in relievo makes a part of this art.

Its antiquity appears from many places of the holy scripture, from the idols of Laban that Rachel carried off, and by the golden calf set up by the Israelites in the desart.

OPTICS.

Q. What is optics?

A. Optics is the science of vision, whether natural as performed in the eye, or artificial, as effected by instruments.

Q. How is vision produced?

A. Vision or the sense of sight, is in all cases produced by the action of the rays of light upon the fine expansion of the optic nerve, in the eye, called the retina.

Q. Pray what do you call light?

A. That quality of certain bodies, whereby

E

they

hey become visible to us, and render others so. Q. Is not the sun the fountain of light?

A. Yes; but in what manner that great fiery mass is fed with continued fuel to keep up his force, is a question equally useless, and impossible to be resolved; whether comets travel from other systems with a provision of this nature, or whether the etherial vapors come from all parts with their supply, is not worth enquiring after. He that made the comet sweep through immeasurable tracts of space, could with equal case, give permanent light and fire to the sun.

Q. Though it appears a task beyond the reach of human abilities to calculate exactly how long a ray of light is upon its journey, in travelling from the sun to enlighten our hemisphere, yet has it not been attempted?

A. Yes; and found to be seven minutes, though it is nearly a distance of seventy millions of miles; consequently light travels at the rate of an hundred and fifty thousand miles in a single second, which is upwards of a million times swifter than a ball from the mouth of a cannon.

MECHANICS.

Q. What is mechanics ?

A. That science which teaches the nature and laws of motion, the action and force of moving bodies; and the construction and effects of all those machines and engines which go by the name of mechanic powers.

Q. What is motion?

A. A continual and successive change of place. Q. What is rest?

A. The continuance of a body in the same place for any time.

Q: Pray

ic

Q Pray explain what is meant by a mechanpower?

A. Any machine or engine by which a man can raise a greater weight or overcome a greater resistance than he could do by his natural strength without it.

Q. How

many mechanic powers are there? A. There are said to be six in number; namely, the lever, by which we lift weights inuch greater than our strength, unassisted, could overcome : the axle and wheel, by which we can lift them to greater heights: the pully lifts them higher still the screw which if it could move without friction, would give him greater force than any of the rest; the wedge used in cleaving wood, &c. and the inclined plane, by which heavy bodies are rolled up with greater ease. And of these all the most compound engines now consist, as clocks, watches, orreries, most sorts of water engines, with an infinite variety of others.

LESSON XIII.

Of Division of Time, or Chronology.

"A little Chronology will be highly useful."

WHAT is chronology?

KNOX.

A. A science that teaches the method of measuring time, and distinguishing its parts. Q. What is time?

A. Time is the duration of things; its parts are centuries, years, months, weeks, days, hours, minutes, seconds, &c. and by these the larger and lesser intervals of time are estimated and measured. Q. What