THE LONGEST MAP OF THE BOSPHORUS / DRAWING STEP BY STEP OF CONSTANTINOPLE] Bosphorvs Thracicvs, der Kanal des Schwartzen Meers oder die Meer-Enge bey Constantinopel... Kaysrl. Königl. Ungar. Ingenieur Hauptmann.

JOHANN BAPTIST VON REBEN, HOMANN ERBEN (Map maker). 

[THE LONGEST MAP OF THE BOSPHORUS / DRAWING  STEP BY STEP OF CONSTANTINOPLE] Bosphorvs Thracicvs, der Kanal des Schwartzen Meers oder die Meer-Enge bey Constantinopel; sambt denen an beiden Ufern desselbern gelegenen Statten, Flecken, Dörffen, Schlössern, Palaesten, Lusthausern, Wasserleitungen; geometrisch aufgenommen durch Johann..., Kaysrl. Königl. Ungar. Ingenieur Hauptmann. 

Baron Philipp Ferdinand Gudenus, Nurnberg, 1764.

Original huge copperplate map engraving with hand coloring. Framed. 82x51 cm. In German with Latin main title. An attractive green, white and red-toned map. In spite of this map being the only known example of the work of Hungarian engineer von Reben, amongst the maps and plans of the city it has taken on a monumental status. Printed on a single page by the successors to Homann who is considered to be the most important map publisher of 18th century Germany and Europe. It is also known as the longest map of the Bosphorus. Von Reben personally paced out and drew the map to scale the accuracy of which was only realized years later when it was compared with measurements made by modern instruments. In the top part of the cartouche is a numbered legend corresponding to the numbers on the map. Each explanation is either numerated or given a letter of the alphabet. The places of importance indicated in the legend include palaces, public buildings, and structures of significance as well as places of worship and the names of settlements. The Byzantine walls around the city are enumerated and named according to their section (sea walls, land walls, and the Golden Horn walls), and their gates are numbered 30-40; important churches 41-42; squares, inns, palaces, and other monuments 43-61 each with their own explanation. "The measurements were confirmed by German aristocrat, Baron von Gudenus. A measuring instrument was used set to walking speed which was fixed at four land miles per hour" (F. Muhtar Katircioglu).; "The Gudenus opus was made up of 30 engravings of which the first 10 were panoramic views drawn from the Swedish embassy in Beyoglu (Pera). The eleventh was the map in question with the purpose of giving a cartographical explanation of  the proceeding panoramas." (Yerasimos). (Source: The maps of Istanbul, 1422-1922: Ayse Yetiskin Kubilay).