Though the school itself had but few students, its residency in Potsdam, connected by rail to Berlin, and the fame of Berghaus attracted many geographers (e.g. Alexander von Humboldt, Carl Ritter and Zeune), cartographers and explorers.

However, he might have picked up this idea during his time in Gotha as the colour scheme was first introduced by Emil von Sydow (1812–1873) in 1838 when he developed a color methodology for landscape features using hachures, where green was depicted for lowlands and brown used for highlands.

Petermann, supported by Carl Ritter and Robert Bunsen, pleaded with the British government to let Heinrich Barth and Adolf Overweg join up with Richardson's expedition to assure that geographical and scientific aspects which they might encounter were taken care of.

When Petermann went to the Gotha Institute part of the original plan was that he would revive the Geographisches Jahrbuch (Geographical Yearbook), which Heinrich Berghaus had edited from 1850 to 1852.

At the suggestion of the manager Adolf Müller (1820–1880) it was decided instead to publish the monthly Mittheilungen aus Justus Perthes Geographischer Anstalt über wichtige neue Erforschungen auf dem Gesamtgebiet der Geographie von Dr. A. Petermann[14] (PGM) (Communications from the Justus Perthes Geographical Institute concerning important new studies in the whole field of geography, by Dr. A. Petermann).

Their relation to several of the Perthes atlases was plainly expounded in the preface to the first issue of 1855: "Our 'Communications' will differ from all similar publications in that they will summarise and graphically illustrate the results of new geographic explorations in precisely executed and carefully detailed maps.

The contemporary map should so depict the earth’s surface that one can not only measure the horizontal positions of and distances between all points and localities, but also clearly distinguish vertical variations, from sea level to the highest summits.

He was a physician, who learned the geographic trade in practice) wrote many articles about geodesy and surveying, they rarely got involved in other technical and theoretical cartographic issues.

In his last article published before his death, Petermann speaks enthusiastically about the newly developed photogravure, which considerably reduced costs per map while also increasing production speed.

He could have come to rival Carl Vogel, but in 1868 he left the Gotha Institute to co-found his own firm, [Heinrich] Wagner & Debes, which published one of the six famous families of German reference atlases E. Debes neuer Handatlas, later called Grosser Columbus Weltatlas), Carl Barich, Arnim Welcker (1840–1859), Ludwig Friederichsen (who worked on the Stieler and PGM from 1859 to 1863, and later founded the geographical society of Hamburg and became very active in German colonial politics.)

In this they were also guided by the more than consistent work of Vogel, and Von Sydow's critical remarks concerning the advantages and disadvantages of certain styles in his Kartographischen Standpunkt Europas.

The density of information did not indicate how thoroughly an area had been explored, for the cartographers selected their data and drafted the maps in such a way as to give a balanced image as possible.

Bartholomew in 1902 phrased Petermann's drive as: "The filling up of the blank spaces of the unknown in his maps had such a fascination for him that rest seemed impossible to him while any country remained unexplored".

All collections (currently estimated at 185,000 sheets of maps, 120,000 geographical works, and 800 m of archives) were acquired in 2003 by the Free State of Thüringen and deposited with the library of the University of Erfurt in its research center in Gotha.

The influence Petermann tried to wield, even as a young man, can best be illustrated by his interference, together with Bunsen and Ritter, on behalf of Heinrich Barth, who wished to take part in the Richardson expedition.

When first Barth and later Vogel failed to return at the expected time Germany frantically tried to discover their fate, much as Britain had with Franklin in the Arctic area.

In 1855 PGM gives only a summary of the routes of the first half of the total tour, on scale of 1:2,100,000, with added profiles along the borders that do not appear on the detail maps.

The other maps in the 1857 issue show rather small details of the routes, not beautifully executed, while in the text a plan of Agades is inserted (I do not know if it exists in Barth's work).

But it was also a case of marketing PGM, as shown in the memoire that accompanied the map, where Petermann wrote: "The basic idea of our map was to give travellers a sure support for the choice of their routes and guarantee the direction of the explorations, to resolve doubts and stimulate the elucidation of the unknown, and to offer a means for friends at home to follow their moves and to judge the value of their labour.

During this two-day meeting Georg von Neumayer stressed the fact that Germany needed a German maritime institute to be independent of other nations.

Petermann jealously reported on the marine surveys in Britain and America, which were realized with governmental support, and he dearly wished such was possible in other nations, especially Germany.

"[34] Heinrich Berghaus, Petermann's teacher, included this information in the right hand corner on his isotherm map of 1838 for his Physikalische Atlas with the text 'possible polar land' [Wahrscheinliches Polar-Land].

Petermann was undaunted in his endeavors to reach the North Pole and demonstrate a possible passage to the Pacific Ocean, even after this expedition had failed in that respect.

We unfortunately do not find his famous six-sheet map of the United States (Neue Karte der Vereinigten Staaten vor Nord-Amerika in 6 Blättern) in the issues of PGM.

This was the case with, for example, the map of the Kerguelen and McDonald Islands sighted by John Heard (1853), William MacDonald (1854), Hutton (1854), Attway (1854), Rees (1854), and Neumayer (1857), with several comparisons of explorations since James Cook.

Petermann's greatest accomplishment lay in the interpretation and evaluation of sometimes contradictory sources, and his great legacy is that he was able to develop this faculty in most of his pupils in such a fine way that geography at large has profited from it ever since.

When Charles Darwin published The Descent of Man it was the beginning of the expansion of human geography, which till then was only rarely focused upon, except in the field of ethnography.

Bartholomew wrote: "It is only a fair tribute to Augustus Petermann to say that no one has done more than he to advance modern cartography, and no man has ever left a more fitting monument to himself than his Mitteilungen, which still bears his name, and under the editorship of Dr. Supan, is the leading geographical authority in all countries.

[Theodor] v[on] Heuglin and count Karl Graf von Waldburg-Zeil I have entered 118 names in the map: partly they are the names derived from celebrities of arctic explorations and discoveries, arctic travellers anyway as well as excellent friends, patrons, and participants of different nationalities in the newest northpolar expeditions, partly eminent German travellers in Africa, Australia, America ..."[44] So the accompanying map of Svalbard is larded with features named after Barth, Behm, Berghaus, Bessel, Brehm, Breusing, Heuglin, Hochstetter, Koldewey, Lange, Mauch, Oetker, Payer, Perthes, Petermann, Ravenstein, Weyprecht, and Wilhelm.

[45] Many of the letters Petermann sent or received have been saved for future study, as also are the drafts he made for many maps, and are kept in the Perthes Collection of the University of Erfurt Gotha Research Library at 'Perthesforum'.