^-;i, MEMOIR RELATIVE TO 



" . 3s great attention has been attrafted to furvfys of tbis nature, 

 fince M. Humboldt's account of New Spain h-s been pubbfbed, and 

 from other confiderations, it is probable, tha^ the work will be thought 

 incomplete, if not accompanied by vertical fe^ions. Hitherto the 

 want of barometers, none having yet reached me in ferviceable condi- 

 tion, has prevented my attempting a continued fedlion, which could 

 fcircely be effefted by geometrical methods only, as no continued hnes 

 of stations could be fele^led, the diflances of which can be determined^ 

 with fufficient accuf'^cy for thispurpofeo 



It might alfo be defirable, that fome approach to a phyficaV mnp, 

 Eiould be had, with a view to facilitate geo'ogical and mioeralogical re<i., 

 f?arches, which may. by poUibility, lead to, important confequenceso 

 It carnnot be doubted, that the mountain diilrids contain the precious, 

 ynetals, From. the welLknow'n fad, rhai the L^ndsof almoft every moun- 

 tain dream are adiduoufly wafbed for gold at^ the. points, where their 

 rapidity diminifhes The tribe of pcqple, wjio. follow, this avocadoPs, 

 ^re denominated Bokm, andtheir.emplpymentis by general; report at- 

 tended with amole profit. The gold dud fupplied by the rivers of 

 jifrica,h^^ long mude an opinion current in Europe, that fome lofiy 

 central landexids, which mvijviv:A South. America, in its mines of the, 

 precious metals— md the fame fpecalation Teems no lefs applicable iq.^ 

 the mountains of central AJia^ 



I piAVE it alfo in view to point out a fcrvice of great practical u'ilifys^ 

 which may be derived to geography from a knowledge of the true. 

 pofition and elevation, of feveral fnowy peaks in the Himalaya, chauij ^ 

 of which my furvey already includes upwards of ituriy, and moil of^ 

 them are vifible from the plains, 



Wi?H fcarcely an excep-tion, furveys in Berigal have been made by,-. 

 t]:^e cpmpafs aad perambulator only^ and thofe who have had muchv 



