WORKS PUBLISHED BY HOLTZAPFFEL & Co. 64, Charimg Croat, and 127, Long Acre, London.

A NEW SYSTEM OF SCALES OF EQUAL PARTS;

Applicable to various purposes of Engineering, Architectural, and General By charles HOLTZAPFFEL. Illustrated by a facsimile of the scales on copper-plate. 8vo. cloth, Price 2s. 6d.

"Mr. HOLTAPPFEL, could not have dones a bitter service for the profession than turning his attention to the construction of scales suitable for their purpose - We have for many years been in the habit of using teales mode of paper, both for estimating and drawing, on account of their cenvenience - We have very carefully examined several of the scales, and knot much pleasure in testifying their accuracy and utiltiy. - The civil Engineer, and Architeets'Journal.

DESCRIFPTVE CATALOGUE OF THE WOODS

COMMONLY EMPLOYED IN THIS COUNTRT, FOR THE MECHANICAL AND ORNAHENTAL ARTS.

INTERSPERSED with Extensive Botanical Notes by Dr. ROYLE, F.R.S., L.S.,

AND G.S., ETC, ETC

The Descriptive Catalogue of the Woods, commonly employed in this country, is extract from Vol I. of "Turning and Mechanical Manipulation" by Charles Hollzapffel. The Catalogue is interleaved and bound in cloth, fur the use of Collectors, Naturalists, and Travellers. 8vo. cloth, Price 2s. 6d.

A NOT SYSTEM of DECIMAL GAGES or MEASURES

Fob Sheet Metals, Wires, and Small Manuactured Articles Genrally.

Including the exact decimal values of the gages now principally used for these purposes in the Mechanical Arts.

This paper is extracted from the Appendix to Vol. II. of "Turning and Mechanical Manipulation," by Charles Holtzapffel. Pamphlet 8vo, in wrapper, price ls.

PRINTING APPARATUS for the USE of AMATEURS.

Containing full and practical instructions for the use of Cowfer's Parlour Printing Press, also the description of larger presses on the same principle, and various other apparatus for the Amateur Typographer.

The pamphlet contains likewise, numerous specimens of plain and ornamental types, brass rules, checks, borders, ornaments, corners, arms, etc etc. Third Edition, greatly enlarged. 8vo, cloth, Price 2s. 6d

HOLTZAPFFEL AND CO.'S GENERAL CATALOGUE

Or Lathes, Tools, and Instruments employed in the Mechanical Arts

GENERALLY.

Stereotype Edition. 1849. 8vo. pp. 72, Price 5d, or free by Post, 1s. 4d.

BRIEF ACCOUNT OF IBBETSON'S GEOMETRIC CHUCK.

H. & Co. beg to announce that they have purchased the remaining copies of the pamphlet written by the late J H Ibbetson, Esq., entitled " A brief Account of

Ibbetson's Geometric Chuck, manufacture, by Holtzapffel & Co., with a Sshetiaa of specimens illustrative of some of its Powers." - Pamphlet 8vo., in coloured wrapper, Price 5s.

APPENDIX (B.) - TO HOLTZAPFFEL & CO.'S GENERAL CATALOGUE.

A NEW SYSTEM OF SCALES OF EQUAL PARTS,

Applicable to various purposes of Engineering, Architectural, and General Science. Illustrated by a fac-simile of the scales on copper late. By Charles Holtzapffel. 8vo. cloth, Price 2s. 6d. Published by John Weale, London. Sold also by Holtzapffel & Co., Engine, Lathe, and Tool Manufacturers, 64, Charing Cross, and 1*27 Long Acre, London.

" Mr HOLTZAPFFEL could not have dons a better service for the profession, than turning hit attention to the construction of scales suitable for their purposes. - We have for many years been in the habit of using scales made of paper, both for estimating and drawing, on account of their convenience We ham very carefully examined several of the scales, and have much pleasure in testifying their accuracy and valitiy." - The Civil Engineer and Architects' Journal.

HOLTZAPFFEL AND CO.'S. ENGINE-DIVIDED SCALES, applicable to Engineering Architectural, and General Science.

As the least expensive fabric, each scale is ruled in the Dividing Engine, on a different slip of card paper, 18 inches long, the figures and inscription having been previously printed dry. By this arrangement the confusion of crowded scales is entirely avoided, and any of them may be applied directly to the drawing, or compared with one another, without the employment of the compasses. The material of the scales and of the drawing paper being identical, they will be found well adapted to the majority of the drawings used in common practice. Numerous experiments on this head are detailed in the pamphlet.

ORDINARY DRAWING SCALES.

A series of 24 scales, containing the usual reductions of the foot, from one sixteenth of an inch to 6 inches to the foot, including three lines of inches, divided into eighths, tenths, and twelfths,and the English foot decimally divided. Sold also in quarter-sets, or singly.

CHAIN SCALES.

A series of 12 scales in chains and links, namely, 1, l 1/2, 2, 3, 4, 6, 8, 10, 16, 20, 30, 40, chains to the inch various others, and also scales of chains and miles expressed in feet.

PROPORTIONAL SCALES.

A series of 25 Proportional Scales, for the enlargement and diminution of drawings and models, so as to suit all transpositions of scale, required by the limitation of the drawing paper, the copper plate, or of the materials to he used in the Lathe or otherwise. The series gives 400 distinct and different ratios of proportion, which are given in a tabular form in the Pamphlet.

COMPARATIVE SCALES.

A series of 24 Comparative Scales, by which any length in Berlin, Brussels, English, Florence, French, Leipsic, Lisbon, Munich, Neapolitan, Polish, Rhineland, Roman, Sicilian, Spanish, 8* Venetian, Vienna, measures, whether in feet, bracchi, palms, inches, or parts, can be transposed on inspection into corresponding quantities, expressed in any other of the linear measures of the series.

The same method is equally applicable to the transposition of the measures, weights, moneys, miles, leagues, etc. of different Countries, and for any of which purposes, scales will be made to order, from the measures of the National Standards given in KELLY's Cambist.