Cartography: brief history by a French teacher of physics. ( Didier Hottois Merlimont France)

                           Cartography  and  Physics


                                                                         en franšais 
"Three hundred francs for this antique map of the town of Hesdin ? Isn't there any connoisseur in the room ?" The decreasing bidding had been going on for a few minutes and yet no customer showed any interest in it.

 "Two hundred and fifty francs ?"

A finger then raised timidly, causing the ivory gavel to bang the desk.

And the auctioneer, relieved, added:

 "Here is my connoisseur ! Sir, you are making a good deal."

Having come here to furnish my house, I was not going back completely empty-handed and my collection of antique maps of the County of Boulogne, of Picardie and of Artois started  that very day.

I must say that " the man with the gavel" was half right. I now know that the object sold was a "Braun Hohenberg", dating from 1580, therefore I had made an excellent deal, but not as a connoisseur.

 I might have become one by studying the vast amount of literature on the subject that I have collected ever since.   I take the path of the amateur who sees in the evolution of cartography close links with the evolution of physics and who also sees in it perhaps a possible way of practising interdisciplinarity in his high-school teaching.

Did Julius Caesar who conquered Gaul from 58 to 51 B.C. have maps ?

Agrippa's Orbis terrarum dating from that period has now disappeared but we know that it was more of a travel itinerary than a map in the sense that we understand it today.

It is possible  to have a close enough idea of it by observing the republished editions (some dating from the 17 th. century) of the "Antiqua Tabula". The towns and villages are joined in a linear fashion.

The documents from the roman period must have been presented as follows:

"In order to go from Lyon ( Lugdunum ! ) to Paris ( Lutecia), you will have to stop by Macon and then by...."

The distance between two stops was also indicated.

Claude Ptolemy ( 2 nd. century A.D.)

It seems that Ptolemy ( we also know him for his geocentric vision of the world) was not really a cartographer but his data have helped to produce the very first maps which were distributed. In our Greek physicist's "Geography" are gathered astronomical measurements ( 350 "fixed" points ) and excerpts from travel logs (8000 places).

 Historical accuracy requires us to mention that Ptolemy's work came to us only through rare ancient manuscripts ( the oldest dating  from the 10 th. century).

Gutenberg (Johannes Genfleisch alias)

During the  12 th.century, the Chinese were producing printed maps (Liu Ching Thu encyclopedia). It would be better to call Gutenberg (in 1440) the inventor of typography rather than printing.

To the reader who would  question this jump of twelve centuries in history, I would point out the fact that the very first map to be widely published (500 copies in Bolonia in 1477) was,  as you must have guessed,  the transcript of the "Geography of Ptolemy".

I    would however have some regret for not mentioning the "Portulans". "Portulans" are nautical charts ( with compass )  realized between the end of the 13 th . century and the 17 th . century. Over that  period, the portulans kept the same aspect of "intermingled segments" but it is certain that the meaning of these segments  evolved  towards a system of graduated data with the rediscovery of the Geography of  Ptolemy.

The invention of printing did  not mean the end of handwritten  maps. For more than two centuries, many printed maps were "polished up" by hand  (annotating and colouring).

Mercator ( Gerhard Kremer alias) 1512- 1594

Certainly the most famous cartographer, he owes his reputation to the projection which bears his name and also to both the quality and quantity of his production.

He was the first to publish an "atlas" in 1585.

We must remember that the projection of Mercator ( still in use today ) keeps relative angles but not surface aeras.

As far as aesthetics is concerned, as a collector, I much prefer Ortelius. Ortelius  was the cartographer of Philip II of Spain and he produced  his "Theatrum orbis terrarum" in 1570 ( 15 years before the atlas of Mercator).

If you do not wish to collect maps of Japan ( record prices !)  with a limited budget you can still find good maps dating from that period.

It is quite interesting to know that some maps of Mercator do not bear his signature; some of  the latter's plates were acquired by Jodocus Hondius (1563-1612 )  a cartographer and manufacter of instruments.

I also have   a preference for Blaeu who acquired some plates of Ortelius and Mercator .

Willem Blaeu settled as a scientific  apparatus maker in Amsterdam in 1599 and, after training with Tycho Brahe, he started printing in 1605. The Blaeu's house and his " treasure" disappeared in a fire on February 23rd, 1672.

 
 

           Mercator  (map dating from the beginning of the 17th.century)

Cassini

Once again, physics is not far away :

Cassini I (1625-1712) studied Venus, Mars and Jupiter and he also discovered  two satellites of Saturn. He is one of the three Cassinis to have been the manager of the Observatory of Paris.

We owe the famous map to Cassini III (1714-1784) and Cassini IV (1748-1845).

Louis XV  kept saying that this map had caused him to lose more territories than he had ever gained in all his wars. France was suddenly losing two degrees in longitude and 3/4 of a degree in latitude.

The physicist in me sees in this meticulous triangulation the very first significant operation of measurements  ordered  in France.

The triangulation and astronomic surveys needed to elaborate the map of France lasted about half a century - until 1789 .

The general cartography was only published as a whole in  1815.

The  plate below, from the encyclopedia of Diderot and D'Alembert, presents various surveyor's instruments used in those days.

  Nowadays, marketed maps and Cassini's maps are still much alike (the only basic difference is due to the printing in colour).

We must not conclude, however, that cartography has not made any progress; once again this scientific branch has gained from the advance of technology.

The importance of aerial surveys during W.W.II is well known.

The satellite image maps   are very popular (  the program SPOT among others.) To know more about the new techniques in cartography, you can  visit  Jean-Marie  Nicolas's page.

Besides satellite image maps, rapid progress is to be expected from its mathematical processing. However, although there is no denying that the theory of fractals allows the creation of virtual coasts and reliefs, and even if self-similarity is evident in the case of the coasts of Brittany, I can't yet see them being equated.  


to contact me: didier.hottois@wanadoo.fr

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           I thank Annie Chatel  for translating this page. FrancitÚ