38 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1791. 



A Meteorological Journal kept at the Apartments of the Royal Society, by 

 order of the President and Council, p. I29. 



Fill. On the Rate of TraveUing, as performed by Camels ; and its Application, 

 as a Scale, to the Purposes of Geography. By James Rennell, Esq., F. R. S. 

 p. 129. 



In a case where there is so little probability, even in a long course of time, of 

 obtaining many fixed points by celestial observations, it is fortunate that the 

 mode of travelling in Africa happens to be such, as serves to furnish a remark- 

 ably equal scale : the rate of the camel's movement appearing to be, beyond all 

 others, the least variable ; whether we examine it by portions of days, or of 

 hours. In the present state of things, 'the former mode alone can be used ; 

 because few or none of the African travellers carry watches with them ; but it 

 may be hoped, that at no very distant period, the time employed on the road 

 may be obtained with such a degree of exactness, as to furnisii the geographer 

 with materials of a far better kind, than any of lliose formed on computation, 

 that have hitherto been exhibited. Mr. R. therefore gives some examples from 

 which he has drawn the proportions for tiie hours and days journey of the 

 camel, under the 1 ditFerent degrees of burthen, wliich constitute what is com- 

 monly denominated the light, and the heavy, caravan. The routes which fur- 

 nish the above examples are determined in their horizontal, or direct distance, 

 by the respective positions of Aleppo, Bagdad, and Bussorah : all of which have 

 their latitudes and longitudes fixed by celestial observations. These routes are 5 

 in number : and all of them have the time given with a sufhcient degree of pre- 



