2G2 Proceedings of the Boycd Society 
A.D. 
Mean mile. 
Mean error. 
1695 Gibson’s maps,. 
. 40 maps. 
1290±16 
no 
1675 Ogilby’s numbers,. 
134 distances. 
1307 ± 5 
65 
1644 Quartermaster’s map, 
11 distances. 
1255±10 
35 
1643 Tenner’s numbers, . 
73 distances, (1375±12) 
no 
or allowing for windings, probably 1280 ± 20 
1610 Speed’s maps, . 
43 maps. 
1300±12 
90 
1575 Saxton’s maps, . . 
30 maps. 
1310±16 
100 
1473 Wm. Worcester’s notes, 92 distances. 
1310±20 
200 
1422 Lannoy’s account, 
5 distances. 
1280±20 
60 
1253 Eoger Bacon’s account, 15 distances. 
1320±60 
480 
1250? Bodleian map. 
130 distances. 
1265± 9 
120 
The question now before us is, what probability is there of any 
change in the popular mile during the four centuries in which we 
have traced it ? The possibility of change certainly lies within 
narrow limits, since (looking to the accurate authorities) the later 
examples cannot be taken to exceed 1307, nor the earlier to fall 
short of 1265.* Xow, it is very unlikely that the Bodleian mile 
was as long as 1300, in fact it is more than 100 to 1 against its being 
so ; therefore, the oldest form cannot be taken as a mere careless 
variant of Ogilby’s value of 1307. Bacon, Lannoy, and William of 
Worcester are all too uncertain to decide on the difference in ques- 
tion. Coming down to the seventeenth century, the Quartermaster’s 
maps, which agree very well among themselves, corroborate the 
earlier value, but we can hardly set them up against the large mass 
of information in Ogilby’s tables. 
On the whole, I should incline to fix the value of the old English 
mile at 1300 ± 10 during the end of the fifteenth and on to the seven- 
teenth centuries, and to suppose that during the fourteenth century 
and the beginning of the fifteenth, it was lengthening from a value 
of 1265=1= 10, which it had in the thirteenth century. As it had 
lengthened thus, it is not improbable that the original value of it was 
still shorter, perhaps not exceeding 1250, or \\ statute miles. In any 
case the range of uncertainty is now reduced to very narrow limits, 
* The mile in Italy having lengthened 1 per cent., though many of the 
old Roman milestones remained standing in the country, shows in which 
direction itinerary measures are likely to change. 
