the quantity o f variation is i8 ° , it decreases with great rapidity, and finally , to nothing, in go in g eastwards to India, or south-westward to South America : and that from the same point, it increases, in go ing NNtV, towards Ireland, o r to the opposite quarter, towards the coast o i Caffraria. B u t the change is not in any proportion so rapid in. the increase, in go ing north or south, as in the decrease, in going east o r west. Such are the outlines of, this sys tem; b y which, i f a person was to 's e t out from C a p e V e rd , o r .C a p e Blan co , to traverse A fr ica from W S W to E N E , to Upper or L ow e r Eg ypt, he w ould find at setting out, from i g f to 1 degrees o f westerly variation, which would increase to 18° about the centre o f the continent, and afterwards decrease to a less quantity than at: his setting out. Mr. P a rk ’ s travels being comprized between C ape V e rd and the centre o f A fr ica , will therefore be in the quarter that has from 1 6 to 18 d e g re e s ; and the part more particularly, where, from the want o f observations o f latitude, w e must depend on his compass bearings, nearer 180 t h a n . i y f * I shall n ow.p ro ceed to the detail o f M r . P a rk ’s materials. L e a v in g Pisania, M r . P a rk proceeded eastward to M e d in a ,t the capital place, and at a given time, is of less importance to the present question, than that o f the hearing o f the lines o f equal quantities, at any recent period : and this object is, I think, tolerably well obtained, by the materials before me. Any change that may have taken place since 1793, is in favour of a greater quantity of variation, within the limits o f Mr. Park’s travels. In the Atlantic, the increase appears to be about a degree in seven years. In the Indian ocean, less: and in the Red sea, there seems to have been little alteration between 1762, and 1776. The lines, as far as they are founded on authority, are continuous; but broken in the parts assumed. * It is in proof of the existence o f this quantity o f variation, that, on closing Mr. Park s route at Woolli, there appeared to be only a small deficiency ¡of distance on the Map, when 170 variation were allowed. Had the quantity allowed been less, this ought not to have happened, as Jarra is placed according to its latitude. f Major Houghton’s point of outset in 1791 was Medina. His route falls into that of Mr. Park at several points, and finally branches off from it about 30 miles short of the Faleme river, which the Major crossed at Calcullo, near zo miles higher up than Naye, where Mr. Park crossed it. o f W o o l li ; and thehce to the E N E , through the countries o f Bondou, Ka jaa ga, and K a s so n ; the two latter o f which are separated b y the riv e r o f Senegal. In his way, he to o k observations o f latitude at K o lo r , Ko o rk o o ran y , and J o a g , on this side the r iv e r : b y which means we are enabled to co r re ct the parallels. T h e distance at present is left as it stands in the Journal, with a v iew o f correcting it afterwards. T h e result o f these bearings and distances (the particulars o f which appear b e low ),* places J o a g at 2 4 7 miles east o f Pisan ia ; and the latitude, b y two different observations, was found to be 14° 25'.+ A t J o a g M r . Pa rk was informed that Dramanet, which is about 2 j miles Hours G. Bearings by Lat. by Miles Compass. Country. Observ. REMARKS. direct * Pisania _ _ _ _ I3° 35" t0 r 6 l 6 SE b y E Y an i On these bearings 17° Jindey - J Koolacunda 5 *3 E westerly variation were allowed. T h e diff. lat. Tabajang - 2 Î 6 E J N was then 89 ; departure Medina - S i 15 ditto easterly 237. But the Konjour - 3 8 E j S diff. lat. by obs. being Mallaing - 2 6 E by S >Wooli only 50, the course should Kolor 5 12 E N E . 13° 49' be E i i * N instead o f Tambacunda S i 14 S E b y E E 2 o f, as before; and Kooniakarry s *3 E by N the departure 247. But Koojar 3 9 E i N . . I have finally corrected the easting, by reducing it 24 miles, or to 223. A t a well - T a llica Ganada *3 4 4 34 10 ro E by N E E j N \Voods Koorkoorany 4} 12 ESE _ Dooggi - i *3° 53' 3 E by N Buggil - 4i 14 E . i N »Bondou Soobroodka 7 18 E by N Naye - - 7 16 E N E Fattyacunda 3i 7 ditto Kimmoo - 4i 12 ditto . _ 14® 25' Joag - - 6 16 E by N Kajaaga f According to this result, Joag would be in longitude 90 12', and Fort St. Joseph in 9® 21 '; which is about 38 min. more easterly than M. D ’Anville’s Map o f the Senegal allows : o f which more in the sequel.
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