Astronomical Instruments and Accessories   By: William Gaertner and Company

ASTRONOMICAL INSTRUMENTS ... AND ... ACCESSORIES.

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WM. GAERTNER & CO. 5345 5349 Lake Ave. CHICAGO.

Catalog A. 1908.

ASTRONOMICAL INSTRUMENTS ... AND ... ACCESSORIES.

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WM. GAERTNER & CO. 5345 5349 Lake Ave. CHICAGO.

Notice.

This catalogue supersedes former editions.

The prices given in this catalogue are net and do not include packing which will be charged at cost.

To avoid mistakes and delays when ordering please give catalogue number and shipping instructions.

Most of the instruments listed in this catalogue are constructed to order only but the smaller sizes of telescopes with accessories, chronographs, simpler measuring machines, etc., are usually kept in stock.

The apparatus listed in this catalogue is of our own manufacture, excepting the astronomical regulator clocks, which we have listed for the convenience of our customers.

All orders will be filled as promptly as possible with due regard to thorough workmanship and efficient inspection.

Everything that leaves our establishment is carefully tested and inspected and we can guarantee our apparatus to be, in every respect, fully as represented. Any piece, which does not come up to the most exacting requirements will always be promptly replaced within the shortest possible time.

We shall be glad to satisfy any special requirements of our customers and will make any desired alterations and additions on the standard designs.

Introduction.

In the following pages we have endeavored to give to our customers an idea of the line of astronomical instruments of the latest and most improved types which we have constructed for some of the leading observatories as mentioned in the text. We feel that this series of illustrations may not only be of general interest, but also of service in helping to determine further developments of modern astronomical and astrophysical equipment. We have not thought it advisable to describe in detail the various instruments of precision, which we have been called upon to construct from time to time for the scientists in the astronomical as well as other branches of science during the last ten years. As a rule every astronomer is interested in some special line of research, which for a successful investigation requires a special adaptation of the instrument he proposes to use, and in such cases we are confident we can fill the requirements and shall be happy to correspond with interested parties. We are in position to undertake the design of special apparatus and can furnish sketches and estimates in accordance with the suggestions of the customer on short notice in such cases, where the importance of the prospective business will warrant it. Among the various instruments which we have built, but which are not included in this catalogue, we wish to mention, spectroheliographs, planetary cameras, photographic plate holders, domes for observatories, etc.

The optical parts which we furnish are of the highest degree of excellence and are made for us by several of the most reliable firms in this line.

Mr. O. L. Petitdidier is closely located to our works, and during the last ten years has supplied most of our objectives, etc.

It is and has been the aim of our firm to produce apparatus of the highest grade and the constant growth of our business is a mute but eloquent testimonial that our efforts have been appreciated by our customers.

We are glad to acknowledge our indebtedness to many of the foremost astronomers, who have greatly assisted us by suggestions as to their particular requirements, and by supplying certain of the photographs here reproduced.

We take this opportunity to thank our customers for the favors rendered us in the past, and trust that in the future these mutually pleasant relations may be renewed.

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