Opis: Remarks on Engineers' Surveying Instruments (Classic Reprint) - Heller Heller

Excerpt from Remarks on Engineers' Surveying Instruments

When we some three years since first introduced our "Improved Transit" to the Engineering profession, we had no idea that it would meet with so immediate favor as it has, especially as we made no particular efforts to spread the knowledge of the improvement. The first public knowledge was conveyed through the paper read before the American Philosophical Society by J. Peter Lesley, Esq., Dean of the Faculty of the new Department of Science of the University of Pennsylvania, as well as Professor of Mining and Geology in that institution; than whom no person is better qualified by extensive practice in the field to judge of the quality of Surveying instruments. On the publication of this paper, we resolved to submit our instruments to a committee of experts to be appointed by the Franklin Institute of Philadelphia. This committee was composed of the following gentlemen: Jno. C. Trautwine, Civ. Eng., author of the "Engineers' Pocket-Book," works on "Excavations," "Curves," etc., and whose knowledge regarding all matters connected with Civil Engineering is too well known to need recapitulation, was Chairman; Saml. L. Smedley, Chief Engineer and Surveyor of the city of Philadelphia; Chas. S. Close, Esq., of the Philadelphia Survey Department; L. M. Haupt, Civ. Eng., Prof. of Civil Engineering in the University of Pennsylvania; and Ellwood Morris, Civ. Eng., author of "Earthworks," formerly Chief Engineer of the Ohio and Chesapeake Canal, and of other works, being the remaining members. After a thorough examination in whole and in detail of the instruments and the principles of their construction, they unanimously made the report that will be found in the body of the pamphlet. In proof of the sincerity of the opinions of each individual member of the committee, we may state that since the report was submitted, the Survey Department of the city have procured from us all the new instruments required since that date, amounting to eight in all; also that the University of Pennsylvania have purchased from us all the Engineering instruments required by that institution; and, moreover, we have sold instruments either to every member of the committee directly, or to other Engineers at their recommendation.

As we have in the last three years made two improvements in Telescopes, word of explanation may be necessary to distinguish them apart. In 1870 we improved the formula in general use for Telescopes in such a manner as to practically annihilate the chromatic and spherical aberration. This Telescope is the one referred to in the Philosophical Society paper, and in the report of the Franklin Institute Committee or Civil Engineers; and this Telescope is on all of our instruments from No. 4100 to No. 4592 inclusive. (All of our instruments are numbered on the face.)

Early in 1873 we commenced experimenting in order to increase the power of our Telescopes, and we only brought our experiments to a perfectly satisfactory conclusion in the latter part of December of the same year. We have made but comparatively few instruments with this new Telescope attached (from No. 4593 to 4646 inclusive). This latter Telescope is, however, the one which we are now placing on all of our new instruments; and it was with a Telescope of this kind on a Transit that we made for the City of Philadelphia Survey Department, that the comparisons as to power, range and definition, as compared with an ordinary Transit Telescope, were made by Mr. Stauffer.

The articles extracted from the editorial columns of the United States Railroad and Mining Register will give the full details concerning the "Improved Telescope;" and the "Franklin Institute Report" first sees the light in these pages. Having within a short time doubled our force of skilled workmen and tools, and having also called in the aid of steam, we hope in the future to supply any reasonable demand on us for instruments, and to

Szczegóły: Remarks on Engineers' Surveying Instruments (Classic Reprint) - Heller Heller

Nazwa: Remarks on Engineers' Surveying Instruments (Classic Reprint)
Autor: Heller Heller
Wydawnictwo: FB &c Ltd
Kod paskowy: 9781332031573
Języki: angielski
Ilość stron: 68
Format: 15.2x22.9cm
Oprawa: Miękka

Recenzje: Remarks on Engineers' Surveying Instruments (Classic Reprint) - Heller Heller