Though the preceding instances are quite sufficient, yet it may be satisfactory to name one or two short distances in which a very large mistake is impossible. The following, were they the only ones, would lead us to suspect that the old mile was even longer than a mile and a half statute. William of Worcester says that Wokey Hole is about half a mile from Wells, whereas, by the Orduance Map, it is a mile and six-tenths in a straight line from the centre of the town. Again, Merkysberry (now Masberry) Castle is placed by him at two miles from Wells on the opposite side : it is now three miles and three quarters in a straight line from the centre of the town. Lastly, Fenny Castle is said to be a mile and a half westward towards the marsh, whereas what is now called Castle Hill is two miles and three-quarters westward. These instances are more convincing than the preceding as to the mere use of a longer mile, though not so well adapted for its determination.
We must now remove the question to Palestine. In the description of the earth given by Roger Bacon (Jebb, pp. 180-236) he generally follows Pliny, and gives distances in Roman miles, except only when treating of those parts which the Crusaders visited, and other Eastern countries. In this part of his account Bacon relics much on the con versation and writings of a certain Williehuus, who went on a mission from the king of France to the Tartars (Turks), in 1253, and on the oral accounts of other travellers. But the country on the distances of whose towns he is most precise in his information is Palestine itself. By taking fifteen well defined instances, and measuring the corresponding distances on Major Rennell's map in parts of inches, we have the following, the first column being the number of leuere in Bacon, the second the number of inches in Rennell. (We omit sea distances, as likely to err considerably.) The scale of Itennell's map is three inches to a degree of latitude; and the only remaining question is, how much must this 16.03 inches, which 6 a total of distances measured in the shortest linen from place to place, be increased to allow for the deviations of the roads I If we assume that the deviation was equal to that in England at the Revolu• lion, we must • inertias:, in the proportion of 100 to 127, which gives 20.35S1. It must be remembered that the more allowance is made for deviation, the longer is the leuca; and wo think it Is the least supposition which can be made, to suppose the deviation on routes in Palestine no greater than in England. 1)r. Bernard states that it was the practice of the Oriental geographer Abu Milan (Al Biruni or Birunius) to deduct one-fifth from distances measured on the reads, to obtain the true distances in a straight line. This amounts to increasing the number of miles measured on the map in the propor tion of 100 to 125, and is practically accordant with the preceding rule in a question of which the data are as rough as in the present ono. The testimony is valuable as referring to roads in the East, and at the period to which Bacon's account refers. The leuca is then, on these, suppositions, of an inch on Bennell'a map, or -0445 of a degree.
The length of the degree in these latitudes being assumed at 363,500 feet, we deduce statute miles as the length of a leuca, or statute miles as the length of the old mile. If we were to reject the correction for deviation, the result would be statute miles, which is unquestionably too small.
In 1422 Sir Gilbert de Lannoy was sent by Henry V. of England, on a tour of military observation in Egypt and Syria. His account is published (from a manuscript in the Bodleian) in the 2lat volume of the Archzeologia.' lie never mentions the league more than once or twice, and gives all his distances in miles. From his account of Egypt we soon found that no hypothesis would make his distances agree with modern travellers. He places the city of Cairo, for instance, three miles from its port Boolak, which distance is now called only one mile. [Kantaa, in Otoo. Dtv.] But on examining his distances in Palestine there appears almost a certainty that he used a smaller mile, of which two and a half (and not two) make the league of Roger Bacon. The following are all the comparisons which his work affords us the means of making :— But even Lannofe mile must be longer than our statute mile ; and it is difficult to explain the difference. One thing is certain, that Lannoy's mile In 1422 cannot be the same thing with that of William of Worcester in 1473, or that of Bacon in 1250, being shorter than either.
So far our conclusions proceed upon assumptions of the highest probability ; and the result is, that from the English measurements we may infer that 100 ancient miles certainly exceed 141 statute miles, while from those in Palestine they are most likely not much less than 153 such miles. It is highly probable that the result is nearer to 153 than to 141. If we were to take a mean of both results, giving them equal weights, the mile thus obtained would be probably too small, and this result is I•47 ; so that (ae mentioned in Lracue) the ratio of 145 to 100 is the very least which is admissible, and perhaps too small even for a minimum. It seems to us that a more probable result would be obtained by taking 153 as a result of the measure in Palestine (for it is hard to believe that the correction for deviation could have been too much), and giving this number twice an much weight as 141 In forming • mean of the two. This given 149 in place of 147; or, roughly speaking, we think it by no means improbable that 100 ancient miles were as much as 150 statute miles, and tolerably certain that they exceeded 145 such miles. At the same time there is evidence enough that very different miles were in use among writers, and also that the most ignorant confusiou between ancient and modern mea sures frequently existed. Sir John 31auudevile, for instance, says, " Aftre the auctoures of a.strononlye, 700 furlonges of erthe aneweren to • degree of the firmament : and tho ben 87 miles and 4 ftirlonges. Now be that here multiplyed by 360 althea ; and than thel ben 31,500 males, every of 8 furlonges, aftre miles of ours contree." The old astronomical authors use the stadium, which is here made to be the English furlong, a measure with which it had no connection.