CAPTAIN GRANT of the 13th Hussars has paid me the compliment of dealing in great detail with, and correcting the errors of, a study on a Roman Road (the Stane Street) which I made a number of years ago and published, if I remember rightly, somewhat before the war. The errors he has discovered and marked shall be duly set right if (as I fear is not very likely!) there shall be enough sale for my old book to justify its reprinting.
But the value of this new monograph* by Captain Grant does not lie in his review of my own amateur and insignificant work, but in something vastly more important. Unless Captain Grant’s calculations are at fault (which is unlikely, for the whole work is very carefully done and the author is evidently an expert in his subject), he has proved a thing of the utmost consequence to all history, to wit, the possession by the ancients of instruments of precision comparable with our own, and of a highly developed art of map-making. Now if that is finally and conclusively established, our whole conception of that Roman civilisation from which we all derive undergoes a vast and complete revolution. We are then dealing, in the first four centuries, not with the elementary science we had hitherto imagined, but with a state of society fully equipped for minute astronomical observation and possessing—presumably—a similar equipment in many other departments of knowledge.
* The Topography of Stane Street. By W. A. Grant. Long, 5s.
Many years ago, when I first began to dabble in this kind of antiquity, I was among the very few at that time to maintain—more from the point of view of common sense than from detailed evidence (wherein I have not the necessary scholarship to be competent)—that, in the nature of things, the high civilisation of Rome in the first four centuries must have possessed a mass of technical instruments and developed science which has been lost.
When I was a young man the academic fad was all the other way. You were always taught that antiquity was childishly ignorant of physical affairs, and that nothing really accurate in that department had been done until the modern advance, which it was the business of this school to belaud. Against this I reacted.
But when it came to following up a Roman road, an amusement in which I have indulged over many such relics in England and a few on the Continent, it never occurred to me that the builders of these great highways could have had instruments of precision comparable with those of our own time, or even of the seventeenth century. Still less that they could have had an accurate system of map-making and any useful production of maps in detail. I did no more, therefore, in the business than follow up the remains of each road I studied, looking for traces in the gaps when it seemed to have disappeared, and noting the heights from which each of the straight sections into which such roads fall seemed to have been “sighted.” I was content to follow the ordnance map and to take angles upon it with a small protractor. For, under the hypothesis we have all hitherto followed, the Roman engineers made only an approximation to the direction they had to follow, and were dependent upon the rough work of alignment by cordons of observers or staffs and signals set upon the ground, in which case the interest of studying their work lay only in following it on the soil. The orientation of each straight section was of little import, but rather the nature of river crossings, the gradients attempted, &c. But now comes Captain Grant advancing the discovery that before any road was planned the segment of a great circle between the distant terminal points was plotted out with perfect precision, and the road planned by that calculation. The theory will have to be tested, of course, on other Roman roads besides the Stane Street, but if it should make good in those other cases and be finally confirmed (as seems to be not unlikely), our whole judgment of European History will demand revision: of such consequence is this one observation.
The old-fashioned view was that the Roman engineers having only a general idea of how the line would lie between two distant points which they desired to join (such as North gate of Paris and Southern gate of Rouen, the West gate of London and the North gate of Winchester) went at their task as men must who have not accurate maps nor modern instruments of survey: that is, they explored the country between the two points, noticed the “roughly shortest way” that had already been developed by the inhabitants of the place, and at last, having thought out a scheme of least effort, planned out their road in great straight limbs from one sighting point to another. They would take a sight from one hilltop to another hill-top within the range of vision and strike an alignment, from one to the other. Then from this second point to a third, and so on. That was how I imagined the Stane Street from Chichester to London to have been plotted out.
But according to the new theory put forward by Captain Grant, the exact measurement of these alignments is of the utmost importance: for this theory is, as I have have said, no less than a contention that the Roman engineers first exactly plotted the points on a great circleUnderlined by AW in cutting passing through the two terminals, and only after having performed that minute observation undertook the actual building of the road. Not only does Captain Grant’s work suggest that the Romans possessed these powers of accurate mapping and survey in detail, but that they corrected and tested their results by a careful triangulation.
Briefly, Captain Grant’s argument runs thus:—
The Roman engineers plotted out with exact accuracy the segment of a great circle joining the Southern end of the Roman bridge at London and the East gate at Chichester. Along this line to a hair the first miles of the road were run, beginning from London. When Ashtead was passed divergence was made in order to avoid contours that might be too difficult, to fix convenient places for camps at intervals of one day’s march, and save inconvenience of water-crossings and what not, but the first miles of the road out of London through Merton Abbey to Ashtead, following as they do exactly the great circle cutting the two terminals, are proof that perfect survey, the most accurate sort, was possible to the Romans and achieved. It means that they had chronometers or the equivalent—otherwise they could not have established longitude to a second—and that they could exercise corresponding accuracy in determining latitude by observation.
In support of this contention, Captain Grant points out not only the exact coincidence of the great circle line with the line through Merton Abbey bridge and on to Ashtead camp, but also the fact that a secondary alignment taken from Burgh Hill, near Pulborough, also aiming at London Bridge, precisely hits the Arun crossing at Aldfoldean bridge. Can two such coincidences be fortuitous?
The only criticism, so far as I can see, which might be brought against the new argument is that we have no certitude of a Roman road running from Ashtead camp to London Bridge, save the coincidence between that line and certain modern portions of metalled road, while a Roman road does certainly stand out on the top of Epsom Downs and does not there correspond with the direct alignment between London Bridge and Chichester. The exact coincidence between the alignment at London Bridge, at Burgh Hill and the corner of Aldfoldean Bridge is very striking, and, if one had to bet, I think the betting would be that the theory applied to other roads would be confirmed, and very eager shall I be to see the progress of full proof supporting so novel and striking a change. It may be that Captain Grant’s theory has been advanced elsewhere before now, but I have not seen it anywhere. It comes to me as a complete novelty, and, if it is a true discovery, everyone will agree that it is of the highest importance to history, for it suddenly changes and raises our whole view of the remote past.
Source info: Journal title (cropped) and date in cutting; checked in library.