C.P.Goerz (Carl Paul Goerz 1854 - 1923) started life selling Mathematical instruments to schools.
By around 1887 his interest turned to selling cameras, this was followed a year later by the take-over of the workshops of F.A. Hintze's, creating the company Optische Anstalt C.P. Goerz.
With this company, Goerz produced cameras and lenses. By 1890, Goerz had moved production
Goerz was not content with just selling one product, and quickly the company was producing
a whole range of various optical instruments. Seeing the potential for Ministry orders, he started to develope a range of binoculars in the late 1890's, and in doing so, he was competing against his major rival of Zeiss.
In the year 1899, Goerz produced a prismatic binocular, which he offered to the German Ministry for testing. This proved successful, for early in the year 1900 an order was placed by the German Ministry and full scale production was started of the model known as "1899".
Zeiss was already using a well established D.F. code system for their Ministry binoculars, so Goerz kept the system and stamped the binocular "D.F.99"
The D.F., stood for "Doppelfernrohr" (Double-Telescope), and this can be traced back to binoculars that Zeiss were producing in the year 1874.
In the year 1903, more orders were placed, and Goerz opened a department at the Berlin factory solely for the production of military optics. The new model was known as the D.F. 03. The Goerz business rapidly grew, and they quickly became the worlds biggest producer of military optics. It was also around this time that they started to produce a series of refracting telescopes.
The year 1903, also saw the company floated on the Stock Market. Never one to miss out on advertising, Goerz proudly proclaimed that his company had produced around 130,000 binoculars by the year 1907.This got under the skin of his rivals Zeiss, who made a counter-claim a year later. It was clear that Goerz was rapidly becoming a thorn in the side of Zeiss. The company also went on to open branches in several countries around the world, including the UK..
Interestingly, Goerz supplied the British War Ministry with optical instruments, and had previously worked with the British company Barr & Stroud, becoming their sole representative in Germany in the year 1898. As part of this agreement, the British company was allowed to send a representative to the Friedenau works, and James French thus worked at the Berlin factory for a year, studying all aspects of optical production.
Goerz was now a highly successful company, and with the out-break of World War 1, yet more business was placed by the both the German and Austrian War Departments. The company was producing binoculars with a 30mm objective version appearing to have been the standard instrument for officers during the War, lower ranks had to make do with Galilean binoculars. Rifle scopes, U-Boat periscopes and searchlights were also produced for the Government.
With the end of WW 1, things quickly started to go bad for Goerz, for the company appears to have struggled in the post war chaos of Germany. The situation was compounded even further by the Peace Treaty of Versailles which prevented Germany producing military equipment. In 1926, the German branch of Goerz was merged with Contessa-Nettel, ICA and Ernemann to form a new company known as Zeiss-Ikon by the year 1927. Zeiss was the controlling share-holder of the new company and declared that lens production would only be carried out by Zeiss, thus the coffin-lid was finely screwed down on their old adversary of Goerz.
During its time, Goerz had produced thousands of optical instruments for both military and civilian use.
( I found this tekst above at Stargazerslounge.com written at 19-04-2009 by "Izar")
This D.F. 99:
The D.F. 99 has a special kind of individual focus ocular, the so called guide-bar [Geradfuehrung] ocular. Turning the ring moves the eye cup and lens up and down, but the ocular does not rotate. [helical focus] (Registered design no. 115394, 1899, 'Ocular focusing for prism binoculars, specified by the fact that the ocular travels in a straight line and is moved by a turnable slide-bar with cord and partitions.') The lenses are tiny, at only 20 mm diameter, and the magnification is x7.
This binocular has a reticule on the left side. It's still collimated and usuable.
Under the name C.P. Goerz Berlin on the left cover is engraved "Ber. A."