Travelling, as performed by Camels. 145 
fhort of the truth. Mr. Carmichael, for inftance, reckons 
the diftance from Aleppo to Bufforah, by the road, at 720 
Britifh miles, although the diredt diftance itfelf fcarcely falls, 
Ihort of it. And Mr. Holford’s road diftance alfo falls very 
fhort* Even Mr. Carmichael’s higheft number of paces, 
would exceed the mean rate given by the experiment at large, 
by a fxtieth part only. 
As thefe gentlemen’s experiments differ only 50 fteps, in 
the mean number, during the hour (one being 2200, the 
other 2150), that is, a 44th part, the error mu ft be looked 
for elfewhere ; and it probably originated in their meafuring 
too fmall a number of fteps on the ground to found their cal- 
culation on. 
The reafon of this great variation in the number of paces, 
in a given time, is the plenty or fcarcity of the Defert Ihrubs, 
on which the camels feed, as they go on ; and thus fuch expe- 
ipents become almoft ufelefs, unlefs the quality of the Defert 
was defcribed in every part. As the hourly rate of Mr. Car- 
michael, coincides with that of Mr. Irwin, within a very 
fmall fra dt ion, although the one travelled in November and 
December, the other in March and April ; it appears, that the 
feafons have little or no effedt in this particular: and it is 
therefore highly probable, that the fhrubs may flourifti in fome 
parts of the Defert, and be dried up in others, at one and the 
fame feafon. 
* 
Vol. LXXXI. 
X 
