Imágenes de página

tub containing a quantity of bran, which is set in motion by turning a shaft that runs through its centre, and thus by means of friction becomes entirely bright. The pin being complete, nothing remains but to separate it from the bran, which is performed by a mode exactly similar to the winnowing of corn; the bran flying off, and leaving the pin behind fit for sale.

LESSON 151. - Hints, 414. From the following Hints, produce a De. scription, developed and expressed as nearly as possible in accordance with the previous rules :

415. MANUFACTURE OF PAPER. 1. European paper manufactured chiefly linen rags ; having been sorted different classes, according respective, first carried to machine cutting table, where into minute parts ; thence engine called duster; which covered wire-net, motion by machinery ; so by rapidity separates dust shreds, forces through wire. 2. Rags reduced to pulp in mills, joint action of water and cylinders, provided with blades ; after which stuff to a repository, supplies vat whence pulp drawn. 3. In order to cast pulp paper, workman immerses in vat mould of wire-cloth, and furnished frame retain stuff. 4. Thus draws much pulp necessary to form one sheet, on which felt, for purpose absorbing moisture ; thus places alternately sheet and felt, till formed six quires paper. 5. When last sheet covered with felt, whole pressed, after which sheets suspended cords to dry.

6. Next operation, sizing, performed, plunging few sheets together, and placing them vessel full of size, into which portion alum thrown. 7. Paper now carried drying-room, and gradually dried, conveyed finishing-room, where submitted action press ; selected, examined, folded, formed quires 24 sheets, finally reams, 20 quires each. 8. This termed writing-paper; adapted purpose process sizing.

9. Various kinds of paper, blotting, brown, coarse papers, not bear ink.

10. To above added, different sorts paper intended drawing, engraving, printing ; which prepared usual way, not sized so papers intended for pen. 11. Among vegetable substances employed substitute linen rags manufacture paper, barley-straw, perhaps, most profitable abundant, serve only common purposes ; unpleasant tinge communicates to paper extremely prejudicial to sight

12. Stained paper made by applying, with soft brushes, any colours used for tinging other substances, after tempering them properly size or gum-water. 13. If paper to be uniform colour, latter be fixed by several thin coatings, each suffered to dry before another applied ; as shade otherwise appear unequal.

LESSON 152. 416. THE ARTS. - Rule 1. In some instances, notice may

be taken of the origin and progress of the Art, with an enumeration of the principal improver's.

2. The advantages conferred on society by a knowledge of this art.

3. Record the various processes by which any work or specimen is produced.

Memoriter Exercise. 417. 1, Read the following Description two or three times, noticing the sequence of the sentences.

2. Reproduce the Example from recollection.

3. Institute a Comparison between your own and the original, when all deviations either in construction, punctuation, or sequence must be nticed.


1. In Stroke-engraving or engraving on copper, the first thing to be done, after the plate is well prepared, is to trace the design intended for engraving accurately on the plate, it is usual to heat the latter sufficiently to melt white wax, with which it must be covered equally, and suffered to cool ; the drawing is then copied in outlines with a black-lead pencil on paper, which is laid with the penciled side upon the wax, and the back rubbed gently with the burnisher, which will transfer the lead to the wax. The design must next be traced with an etching needle through the wax on the copper, when, on wiping it clean, it will exhibit all the outlines ready for the graver.

2. The table intended for engraving on should be perfectly steady, and the sandbags placed equally firm ; in cutting curved or undulating lines, the graver must be held still, or moved to suit the turning of the plate with the left hand, but when straight lines are intended, the plate is to be held stationary, and the graver urged forward with more or less pressure, according to the thickness of the line. Great care is necessary to carry the hand with such steadiness and skill as to prevent the end of the line from being stronger and deeper than the commencement ; and sufficient space must be left between the lines to enable the artist to make those stronger, gradually, which require it.

3. If any accident should occur by the slipping of the graver beyond the boundary required, or any lines be found to be placed erroneously, they are to be effaced by the burnisher, which leaving deep indentings, these must be levelled by the scraper, rubbed with charcoal and water, and finally polished lightly with the burnisher.

4. As the uninterrupted light of the day causes a glare upon the surface of the copper, hurtful and dazzling to the eyes, it is customary to engrave beneath the shade of silk paper, stretched on a square frame, which is placed reclining towards the room near the sill of a window

5. Such are the directions and means to be employed in engraving historical subjects : indeed the graver is equally necessary for the completion of imperfections in etching, to which must be added the use of the dry point in both, for making the faintest shades in the sky, architecture, drapery, water, &c.

LESSON 153. Hints. 419. From the following Hints, which are given in regular succession, produce a Description, developed and expressed as nearly as possible in accordance with the previous rules :

420. ORDERS OF ARCHITECTURE, 1. To Greece indebted for three principal orders architecture, Doric, Ionic, Corinthiun; Rome added, both formed out former, Tuscan, and Composite.

2. Each has particular expression ; that a building or different parts building, rude, solid, neat, delicate, gay, as Tuscan, Doric, &c., employed.

3. Columns these orders distinguishable common observers, by reason ornaments peculiar to capitals; but scientific difference consists in proportions.

4. Tuscan order characterized by simplicity strength. 5. It is devoid ornament. 6. Doric enlivened with ornaments in. 7. Ionic ornamented with volute scroll or spiral horn; its ornaments in style of composition between plainness of Doric and richness Corinthian. 8. Corinthian order known by capital adorned with sorts of leaves ; between these rise little stalks, of which volutes support highest part capital formed. 9. Composite nearly same as Corinthian with addition of volute. 10. In private buildings Roman architects followed Greeks ; but in public edifices surpassed them in grandeur. 11. Dark ages which followed destruction Roman empire, classic architecture Greece Rome lost sight of, but again revived by Italians at the time of restoration letters.

12. Gothic style called because first by Visigoths ; but at first vastly inferior to now called Gothic, which exhibits grandeur and splendour with accurate execution. 13. Saxon and Norman styles called because respectively used Saxons before Conquest, Normans after, building of churches. 14. Saxon style distinguished by semicircular arch, seem to have taken partly from Romans partly from ancestors on continent. 15. Norman distinguished following particulars : walls thick, generally without buttresses, within without, semicircular, supported by columns.

LESSON 154. Original. 421. From the following Objects, let the pupil select two or three with which he is most familiar, for analysis and description, according to the preceding rules :

1. Describe the Air-Pump ; or Siphon; or MagicLantern.

do. Steam-Engine; - Paper-Mill; - Watch. 3. do. The Loom ; A Piano ; — Printing Machine.

LESSON 155. - Original. 422. From the following Subjects let the pupil select two or three with which he is most familiar, for description:

1. Describe the munufacture of Woollen-Cloth ; Pottery; - Calico. 2. do.

- Steel ; - Leather. 3.

the process of Dyeing; Printing ; Wood-Engraving.

4. Describe the origin, progress, and advantages of Chemistry 5. do.


Agriculture 6. do. do.

Commerce. 7. do. do.


ai ori

Silk ;

« AnteriorContinuar »