Brussels International Map Collectors' Circle

BIMCC Newsletter No 20 • September 2004 (abstract)

How to look at ancient maps - A few practical tips

The BIMCC has already been giving some important information for map collectors. In the Newsletter No 9, January 2001, Rodney Shirley's Ten Key Points For The Map Collector were reproduced. The Seminar on 19 February 2000 broached several topics connected with basic knowledge of cartography. The present paper has certainly not the preposterous ambition of being a course on or an introduction to historical maps. It merely aims at being of some use in pinpointing simple facts, generally well known but sometimes overlooked by map lovers in describing their treasured possessions.

A map is a picture: it presents a nice ensemble of well-balanced features which represent a territory, be it large or small. Enjoy its beauty!

A map is a geographical representation of a portion of the earth. It has to be as correct a rendering of an utterly impossible to achieve exactness. A bended surface, however small, is distorted when flattened as on a sheet. A globe gives a correct representation, but, with the exception of some giant ones, it is of necessity too small to be practical.


Old printed maps are frequently referred to under the name of their editor, thus Ortelius, Blaeu, etc. This is quite right, as these cartographers were responsible for the issuing of the map and were often deeply involved in the making of it, to the point of being the sole author. Mercator, Surhon and even Ortelius in his historical maps were the true creators of their maps. Notwithstanding this, several names can appear, as the cartographer gives due credit to the original author of the data on which the map is based, the sources being thus stated in the cartouche or the text. The engraver, often unknown, has sometimes signed his work and, in a few instances, can be the real author.

Nevertheless, new editions can bring confusion: Mercator's maps were edited again by Jodocus Hondius, later by Willem Blaeu. The copper plates were expertly duplicated for Jodocus' son Henricus, which resulted in a fierce competition between the two publishing houses. Sanson's maps were used by Jaillot and copied, quite legally, by Mortier. Frederick de Wit sometimes erased the names of previous cartographers and replaced them by his own, after buying the copper plates. Another trap lies in the name Janssonius, which can refer to Guilielmus Janssonius, i.e.Willem J.Blaeu, also known for a short time as Guilielmus Caesius; more usually, it indicates Joannes Janssonius, Hondius' son-in-law. The dynasties of cartographers sporting the same first name, as the Visschers, don't make identification easy and the latinization is a further difficulty. This use of Latin for placenames has, many years ago, been the source of a funny mistake: "Aug.Vindel" became the mythical cartographer Auguste Vindel, instead of Augusta Vindelicorum, the city of Augsburg!


The size of a map gives an immediate idea of what can be expected of it. A 25 x 30 cm map of Asia will, of course, be a simple one, giving very few details. The same dimensions for a small town can be rather adequate and will give a fairly good picture of streets and blocks. These dimensions of the map can be given between the neatline, i.e. the printed line bordering the map and separating it from the margin. They are thus stated by picture specialists, for whom the complete engraving is most important. In some cases, an ornemental border is added, which is part of the print, but not of the map itself. The better way to describe it then is to measure the "real" map and adding the extra centimetres, eventually between brackets, not to give the false impression that the map is larger than it really is.

If a small portion of the map lies outside the borderline (an overedge), better state it. It happens when there is a kind of "tail" protruding from an otherwise rather regular territory, but which is part of it.


The scale of old maps is never the same in every direction. The distances between towns is thus not exactly measurable, but good maps achieve a tolerable result. Triangulation was either not widely used or poor, with a few remarkable exceptions in manuscript maps. Large scale estate maps can thus be extremely well drawn, with full attention given to all details in relation one to the other. But for the average map, the actual position of villages, towns, hills, even of rivers is generally not exact. Corrections have thus to be introduced when one tries to make measurements between the many features. Some distances and angles are quite acceptable, others are below par. Rather often, measurements in one direction give better results than in other ones, according to the distortion of the map. Several methods for screening have been proposed these last years in journals, not always very easily to be used by the layman. Simple comparisons between situations on an old map and the equivalent modern one can always be made with a protractor. This gives the user a fairly accurate idea of relative distortion.


Scales might seem less important at first sight, but for the comparison of two maps of the same region they become a major help in understanding them. When no scale is mentioned or one of which the units are not quite clear, the scale can be estimated. For a map of a whole continent or a large area, measures of degrees can be taken between latitudes -if there are any! One degree corresponds roughly to 111 km. This is only an approximation, as a degree near the Equator has not the same value as at 50° north. So it is preferable to state between which parallels the measurement was made. Measure the centimetres on the map and compute the scale. As an example, 5 cm for 111 km or 11 100 000 cm give a scale of 1/2 220 000. Drop the last significative figures, as they are not exact and write "circa" or +/- 1/2 200 000. Thus one has an indication of the actual scale, fairly adequate for the average user. The main drawback is that the paper of two copies of the same map can have "lived" differently, with as much as 1 cm difference on 50 cm! Nevertheless, with the circa before the scale, the result is acceptable.

For a small area, the distance "as the crow flies" between two conspicuous features can be measured. This will be the centre of the markets of two villages, the entry and exit of a river in a town or two large buildings. The measurements are taken on a modern map at a known scale and calculated for the old one, provided one keeps in mind the inevitable changes which occurred, as in the encircling walls. Again an approximation, hence the circa, but enough for classifying the item.


World maps are mostly orientated to the north, although al-Idrisi's well known map of the Mediterranean world in the 12th century has North Africa on the top. The Australians have sometimes playfully complained that they are always at the bottom! In smaller areas, the orientation can be anything. The map of the Forêt de Soignes, the first work ordered by Ferraris to prove the skill of officers and cadets in surveying and as a test for the large map of the Austrian Netherlands in the last third of the 18th century, is orientated to the south. Many town plans with or without their neighbourhood are drawn in such a way as to occupy the greater part of the -very expensive- copper plate. Blaeu's beautiful plan of Brussels of 1649 is orientated to the south-east, the greatest dimensions thus fitting on a double page of the town atlas. The point of vantage chosen for sketching a town has also consequences for the orientation of the resulting map.


Few maps are as thoroughly dated as some British Admiralty charts. The survey is naturally stated, but also all the corrections, minor and major, which have been added, first as manuscript notes, then printed. A new chart is edited when there are too many of these dated additions, but is immediately complemented, so that the number of dates can be somewhat bewildering. Be sure to look at the most recent one.

A date gives the precise moment of the "birth" of a map, but there are pitfalls. Joan Blaeu's plan of Brussels is to be found in the famous town atlas of 1649 and the one by Eugène-Henri Fricx bearing the date 1711 is part of the 1712 atlas. So far O.K. But this Fricx-map exists in other states, with differences in the lay-out of streets and the disappearance of an inner gate, blown up in 1727. The engraved date is still 1711! The magnificent wall map of Brabant with the cartouche bearing the name of C.J.Visscher and the date 1656 was actually edited by his son, after the father's demise. Furthermore, one sheet of an existing copy shows a line of fortifications built at the very end of the century and a battle fought in 1703. No change of date, so that only perusing the map reveals the late state.

In the absence of any date, such details are to be checked. For instance, a map of Hainaut showing Charleroi is, of necessity, drawn after 1666; it possibly will be a French one, as the brand-new fortress was captured as soon as 1667; Philippeville goes back to 1555. The fluctuating borderline between countries and the conquest of a city are guidelines for dating, as anyone knows. A double frontierline is sometimes drawn, to show the two possibilities, as during the wars of Louis XIV. Maps with printed text on the back, as these by Ortelius or Mercator-Hondius, can be dated through referring to the existing carto-bibliographies, as details of printing, letters and figures at the bottom reveal from which atlas they were lifted. So one is confronted with two exact dates: that of the first issue and that of the later edition. Both can be stated.

States and aspect

Copies of the same printed map can present a very different aspect. A copper plate enables the printing of a number of copies. Then wear obliterates the clearness of the engraved lines. The plate is corrected in the weak spots and used again. The printed line, after being faded, is again clear, but usually broader. Some mistakes have also been corrected, additions are made, producing new states of the same map. Eventually, rents can appear in the plate revealed by thick black lines on the paper; they are hastily patched, leaving holes round the tear which show conspicuously on the printed sheet (like old-fashioned laced corsets). This can be seen on later copies of the map of the Southern Netherlands, first edited by Fricx at the beginning of the 18th century. And lastly, a new copper plate is engraved, reproducing faithfully the old one, thus adding to the confusion of the potential buyer, confronted with different states of one map and different maps looking very much the same! Details in the engraving can betray the renewal of the copper plate. However skilful the copying engraver, some small alterations prove the change. Hence the absolute necessity of a rather strong magnifying glass in the basic equipment of a map lover or collector.

Modifications can occur in the cartouche without any on the map itself, constituting a new state as a picture. It is not of major importance for the map collector, except that it can sometimes help in the dating. Late 17th and 18th century cartouches are often gorgeous to the point of exuberance.


Legends are absent from the oldest maps. When they exist, they generally state the differences in size of towns, whether fortified or not. Later, large abbeys and the most spectacular features are added, but the real complete legends only go back to the beginning of the 19th century. They give full information on topography, mountains or hills, waterways, marshes, human achievements, even statistics. The most elaborate legends, without which a sheet would be illegible, are those of the geological and pedological maps, the first edited ones being hand-coloured.


Coloured maps are often preferred above black and white ones. But it must be stressed that the engraved lines themselves come out much more beautifully when no colour obliterates their clearness. Yet colour increases the price. Beware of the time honoured "coloris d'époque". It doesn't mean anything! The dealer should state that the colouring occurred in this or that century or is original. Then he pledges his guarantee.


Old maps were usually printed on strong, heavy paper of excellent quality, although there are quite a number on thin, delicate paper, linen or silk. Paper maps are often somewhat foxed, showing brown spots and a yellowish or greyish aspect. The temptation to clean them, reviving their original beauty, is great. In the 19th and well into the 20th century, several methods have been used with damaging effects: partial destruction of the paper or resulting in a blue basic tint, due to reaction to the ill-chosen products. Great care has to be taken to prevent or remedy such evils. Some self-appointed restorers are not to be trusted. The competent ones are both expensive and overworked.

Mere foxing can be overlooked, the alteration of the paper due to acid old ink and green colour is much more dangerous. Here treatment is necessary to prevent small pieces of paper coming loose, following the printed and coloured lines and leaving holes in the map. Intervention is also often needed for maps of the 19th century, the paper of which, made of wood, suffers from acidification. Happily, the quality is still better than that of newspapers, which are threatened by total destruction.


To study a map it is also much easier to look at an unframed one. One can see the possible text at the back and check the reference books. The watermark of the paper is visible, which helps in finding origin and date, although this gives no full certitude. Some few maps have been drawn or printed on old paper at a later date. This can be considered as a forgery, but some people have been caught by this, happily seldom operated trick.

Now and then, a framed map can hide an unpleasant surprise. The map can have been patched or badly repaired. A lady once showed what she thought was a beautiful coloured map, which proved to be a good reproduction. This was immediately seen when the cover glass was taken off and a magnifying glass revealed the triple colour points of the printing.


Try not to keep your larger maps folded. This is a main problem, as no really good solution exists, except if you have many empty walls. Cutting the map and pasting it on linen or paper permits folding, but sacrifices the unity and the possible text on the back. Rolling the map provokes wear at each consultation. A large cabinet with numerous drawers is, of course, the best but is very costly, heavy if the collection is extensive and demands space. If you are lucky enough in acquiring a specimen of a wall map in separate sheets of medium size, keep it so and don't "show it off" as a beautiful ensemble, even if it means frustration. Anyway, console yourself in remembering that light is pernicious for paper and colours.

As a rule, if a map catches your eye, you really like it and you can afford it, you will not be disappointed. Love at first sight also plays its part in cartography!

by Lisette Danckaert