M r . P a rk ’s bearings and distances, and then to co rrect the, bearings ;fey(his ôbservèd latitudes, ás far as th e se : ex tend : and beyond, that, ;I 'have, [taken his bearing b y compass, and allowed the supposed quantity o f variation.; “ T h e result o f these cálculatíOnss 'together with the addition o f his lin e o f distance from Ségo to T om b ù c tò o , Was then compared with th e popular rep o r t o f the distance between the several stations b fW o o I l i , F o r t St. Joseph, Bam b o u k , and T om b u c to o . I t was found that these repo'rts did not materia lly differ from the aggregate distance g iv en b ÿ Mr* Pa rk ; although:they fe ll short o f i t ; a. difference which might naturally 'have béen expected j arid which I h av e ventured to alter. T h e difference, h ow e v e r , dobs n o t exceed tw en ty T o u r geographic miles ; a mere tr ifle in A fr icán geography! T h e pos ition o f T om b u c to o , so obtained, differs on ly h a lf a degree in latitude, and still less in lOngittide, from that arising from the intersection o f the lines b f d istance from M o ro c c o on the N W , and F e z z a n on thé N E : o f which a particular ac coun t will be given in the sequel. A gréât part o f M r . P a rk ’s geographical mémorandums are totally lost : b u t fortunately his bearings b y compass durin g a great-part o f the w a y , aré p reserved. I n other parts, he has preserved only the calculation o f latitude and lon gitu d e , arising from them ; w h ich , h ow e v e r , o f course furnish, the means o f obtaining the bearings, i f necessary. A s he omitted to take observations to determine the quantity o f the variation o f the compass, after he lost the means o f correcting his co u rse b y observations o f latitiide, whiçh Was at Ja rra, about midway in his r o u te :* it becomes a qu e s tion ,o f some importance, what quantity to allow on those lon g lines o f dis tance between Jarra áhd S illa ;; S illa and Manding. ; I t appears on in q u ir y , that the quantity o f variation is no mòre kn ow n , 'an y Where withm the continent o f A jr ic à y \than within, .that o f N çw Holland A r id it happens moreover, that the Unès pfi-eqûal: quantíties-loi. -variation,j fio not run across A fr ic a with that: degree o f regularity and parallelism, which takes place Over great part o f the A tlan tic and Indian oceans (at least this is what appears clea r ly to my judgment) : sò that it becáriie necessary to inquire, what quantity prevails in-the surrounding seas; and What the ge'neral * The places of observátion aré marked 'on’the Map by asterisks.
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