[Broadside, scientific instruments] Electrical APPARATUS of Hartman & Braun ... late E. Hartmann & Co Wurzburg

Francfort o. M.: Hartman & Braun, 1901. Very Good. 29 3/4 x 19 5/8 inches. Fragile broadside printed on thin tissue with multiple folds. Purple stamp of sole American distributors "James W. Queen & Co, SOLE AGENTS, IN NORTH AMERICA (DEPARTMENT No. 40)" with the same printed in text as part of the broadside at the bottom. "The company was founded by Eugen Hartmann in 1879 in Würzburg as "optische Anstalt, physikalisch astronomische Werkstätte". In 1882 Wunibald Braun, brother of physicist Ferdinand Braun became an associate, and in 1884 the company moved to Frankfurt. In 1901 the company was incorporated..." becoming Harman & Braun AG. In (truncated) the 20th century, the company branched into control systems and is still represented today as a legacy part of the industrial conglomerate ABB.

Printed by Knauer Brothers, Francfort o. M. [Frankfurt am Main], this broadside was printed specifically for the American market, with instruments identified in English, and the sole American Agent JAMES W. QUEEN prominently displayed at the base of the broadside. Awards from 1879, 1881, 1882, and 1884 exhibitions are illustrated at the top. Further research on the instruments offered should narrow down the broadside's printing date.

The companies' early scientific instruments as represented on this broadside are found in many institutional collections, including the Science Museum in London, Harvard, and others. The intent to produce breakthrough instrumentation is evident in the illustrated instruments, many marked as designed by Prof. Kohlrausch, a physicist and innovator in this field. "Kohlrausch in 1895 succeeded Hermann von Helmholtz as President of the Physikalisch-Technische Reichsanstalt (PTR- Imperial Physical Technical Institute) an office he held until 1905. There he focused on experimental and instrumental physics, constructing instruments and devising new measuring techniques...under the direction of Kohlrausch, the PTR created numerous standards and calibration standards which were also used internationally outside Germany...He improved precision measuring instruments and developed numerous measuring methods in almost all the fields of physics known during his lifetime, including a reflectivity meter, a tangent galvanometer, and various types of magnetometers and dynamometers. The Kohlrausch bridge, which he invented at the time for the purpose of measuring conductivity, is still well known today..." (Wikipedia)

We have been unable to trace another example of this broadside. In general, large broadsides illustrating scientific instruments are scarce.

LITERATURE:
Davis and Dreyfuss, "The finest instruments ever made", p 159, showing a single known catalog by Hartman & Braun from 1908. (Inventory #: 29334)