Works Published By Holtzapffel & Co

64, Charing Cross, and 127, Long Acre, London.

A New System Of Scales Of Equal Parts;

Applicable to various purposes of Engineering, Architectural, and General Science. By Charles Holtzapffel. Illustrated by a fac-simile of the scales on copper-plate. 8vo. cloth, Price 2s. 6d.

"Mr. Holtzapffel. could not have done a belter service for the profession than turning his 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 have very carefully examined several of the scales, and have much pleasure in testifying their accuracy and utility." - The Civil Engineer, and Architects' Journal.

Descriptive Catalogue Of The Woods

Commonly Employed in this Country, for the Mechanical and Ornamental 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 extracted from Vol. I. of "Turning and Mechanical Manipulation" by Charles Holtzapffel. The Catalogue is interleaved and bound in cloth, for the use of Collectors, Naturalists, and Travellers. 8vo. cloth, Price 2s. 6d.

A New System Of Decimal Gages Or Measures

For Sheet Metals, Wires, and Small Manufactured Articles Generally.

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 1s.

Printing Apparatus For The Use Of Amateurs

Containing full and practical instructions for the use of Cowper'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

Of Lathes, Tools, and Instruments employed in the Mechanical Arts generally.

Stereotype Edition. 1849. 8vo. pp. 72, Price 6d., 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, manufactured by Holtzapffel & Co., with a Selection of Specimens illustrative of some of its Powers." - Pamphlet 8vo., in coloured Trapper, Price 5s.

Advertisements

HOLTZAPFEL and Co. beg to apprise Amateurs and the Public in general, that they have constantly on tale a very large assortment of the tools, instruments and machines, employed in Turning, and Mechanical Manipulation, of the extent of which variety, some small idea may be formed from the succeeding pages copied from their last general Catalogue. Stereotype Impression, 1844. The following Instruments have just been added to their Collection.

The Apostadometer, Or Off-Set Instrument

Invented by W. Petrie, Esq.

Registered 9th Sept, 1846, and Manufactured solely by HOLTZAPFFEL& Co.

This Surveying Instrument is intended for measuring distances, and their direction, with great despatch. It is applicable in a variety of operations, particularly for taking off-sets, for checking surveys, and for facilitating chaining work generally. By this instrument offsets are taken by one simple observation, without the necessity of moving from the Chain-line from which they arc measured.

The Apostadometer is used somewhat as the Sextant, by observing the coincidence of two reflections, and is portable, simple in operation, and trustworthy in its results. It takes off-sets of five chains or more, with the exact right angle, at the same time; and their lengths are read off directly from the instrument without any calculation, etc Off-sets of the ordinary length arc given within a small fraction of a link.

A full description of the Apostadometer may be had on application, price 6d., or free by post, 8d.

Holtzapffel & Co.'s Pen Holder For Enfeebled Hands. Registered 16th Sept, 1846

This was invented for the use of those persons who from age, rheumatism, gout stiffness in the joints of the fingers, defects in the nerves of the hand, paralysis or other infirmity, are deprived of the free use of the fingers, so that they cannot hold a pen in the customary position.

The shaft of the Pen-holder for Enfeebled Hands, is held quite vertically in the central part of the hand, and grasped by the whole of the fingers; this position the most infirm can usually command. The lower extremity of the shaft is allowed to rest firmly upon the paper and thereby support the hand, whilst the tube that actually receives the pen or nib, is jointed to the vertical shaft at about the angle of 45 degrees, and is pressed on the paper by a feeble spring, so as to assimilate in the closest manner to the action of an ordinary quill pen,

The Penholder is adapted to receive a gold, steel, or quill pen at the option of the individual, and the instrument is convenient for the pocket, as it folds into the size of an ordinary pencil-case. Instructions for using the Pen for Eufeebled Hands, with a diagram, free by post