276 On Wheel-Carriages, and the Incapacity of most Roads 
red Sandstone formations: one, the oldest, rests immediately on 
transition or primitive rocks: the other, and newer, rests on beds 
of magnesian limestone, coal, and mountain Limestone, which 
are superimposed on the oldest formations.” 
My object in the present address, is, respectfully to request the 
favour of you, to mention in an early Letter to Mr. Tilloch, for 
insertion in the “ Philosophical Magazine,” the names of two or 
three of the English Mineralogists (and the volumes and pages of 
their Writings) to which you appear to me to refer, in the pas- 
sage above quoted, who were, prior to December 1814, generally 
agreed, in considering the newer red Sandstone formation, as 
resting on beds of magnesian limestone?: or else inform me, 
wherein I may have misunderstood this passage. 
You will likewise do me additional favours, if you will inform 
me in such Letter, whether the term ‘ newer red Sandstone,” 
alluded to in the above extract, was intended for ‘he same_for- 
mation, as was mentioned in one of your Lectures in April 1815, 
as it has been quoted, or referred to in substance, in vol. xlv. 
p- 381, of the Philosophical Magazine, by a Gentleman from 
Bristol, who was understood, to have been then some months 
studying in your College at Edinburgh? : and, whether from the 
middle of page 622 to the end of your Paper above referred to, 
you mean to be understood, when speaking of ‘* the red Sand- 
stone,” as intending only the oldest of the two mentioned, or 
© old red sandstone”’? 
I am, sir, your obedient servant, 
To Mr. Jameson, Joun Farey Sen. 
Professor of Natural History in the University 
of Edinburgh, and President of the Werverian 
Society, &c. 
XLIX. On Wheel-Carriages, and the Incapacity of most Roads 
to sustain the Wear of very heavy Loads. By Mr. Joun 
Farry Sen., Mineral Surveyor and Engineer. 
To Mr. Tilloch. 
Sir, — Tue subject of Wheel-Carriages being at the present 
time, one of some interest, from there being a Committee of the 
House of Commons now sitting, to inquire into the state of the 
Highways, and to report on any matters which may conduce to 
their improvement and better management, I am induced to 
notice some points in the Letter of Mr. Henry Meikle-in your 
last Number. Mr. M. in pages 199 and 200 (as well as Mr. 
Wingrove in p. 14) mention, that the Legislature have restricted 
it to a uniform distance, at which the Wheels of Carriages should 
run 
