THE PREFACE. 



^iUovjances for the federal Windings and occafional De'via" 

 tions that were made out of the direct Road. In our Pajfage 

 through the Mountains and For efts, or "where thePlains isjere 

 cut through nsjith Rivers, [for we met with no Inch fur es any 

 where to moleft us) it frequently happened, that when we 

 had travelled eight Hours, i.e. twenty four Miles, I found, 

 hy the Method above, that, ^^/^r^ Longitude or Lati- 

 tude were concerned, they were to he efiimatedfor no more 

 than twenty or eighteen, z^s often alfo as J had an Oppor- 

 tunity, I took the Meridian Altitude , with aBrafs ^adrant 

 of twelve Inches Radius, which wasfo well graduated, that 

 I could diftinguifh the Divifion upon the Limb to at leaft one 

 \i"' Part of a Degree, iflhu Operation the Arabs call 

 The weighing of the Sun.) Towards the further carry^ 

 ing on Ukewife of thefe Geographical Obfervations, I had a 

 Pocket Compafs, with the Needle well touched', the Varia- 

 tion whereof was, at a Mean, in the Kingdom of Algiers, 

 (AD. ^l^l.) fourteen Degrees, to the Wefiward, and in 

 the Kingdom of ^wxmfixteen \ to which in like Manner I 

 paid a proper Regard, in laying down the Maps and Geo- 

 graphical Obfervations. 



The fever al Degrees of Longitude, that are marked in 

 the Maps of the Kingdoms <?/ Algiers and Tunis, have 

 London for their firft Meridian. The Middle of the 

 Eclipfe of the Moon, (July 28. 1729.) being obferved by 

 Mr.Profejfor Bradley, to fallout ^/Wanfted at i f. d . i i' 

 apparent Time ; and by the French Mifjionaries, and my- 

 felf, at Algiers, at I'^K 14 {proper Allowances being made 

 for theDifference of the Meridians <?f Wanfted and London) 

 willfituate Algiers, at 5 2'. ^o" Ea/i of the latter ; or a few 

 Minutes only more Wefterly, than it is laid down in the 

 Maps and Globes of Mr. Senex. 



The prickt, or double Lines that are traced out upon the 

 Maps, jhew the Places, they pafs through, to be laid down 

 according to my own Obfervations. Mr. Sanfon, an un- 

 fortunate Surgeon and Native of Holland, who hath many 

 Tears attended the Viceroy of Conftantina a^ his Slave, hath 



c fup- 



it 



