Iq^ s^ceet lock. 



^lofe of il)^ rivers, and that the rivers form by the abundance 

 fjf their i^valers, thofe rapid tlood-tides which are obferved on 

 ^he great rivers, fuch as thofe of the river Amazons, which 

 afcend from 5 tp 100 leagues, thofe of the Senegal, which 

 advance almoft as far up, and thofe of other rivers almofl 

 eq^ually confiderable. M. Sorbie thinks that the Mafcaret, or 

 the Pororoca, have altogether the fame caufe as the flood-tide 

 of rivers, and though fome flight fecondary efledls occi:r, 

 fuch ja$ thofe related, that all arife from the fame phy'fical 

 taufe. . 



■KtiTi 



jiifquifitioa 

 upon locks* 

 The common 

 lock. 



Bolt, key, 

 wards, pick- 

 locks, flceleton- 

 keys. 



: Defarifiion of a fecret Lock of ten thouf and Combinations, 



JL HE comnion lock ufually confifls of a bolt, which requires 

 a particular inftrument, called the key, to pufti it backward 

 and forward ; and in order that this bolt may be inacceffible to, 

 violation, certain impediments or pbftacles, ufually called 

 w^rd?,, ^re int^rppfed between the key-hole and the bolt, 

 \H'hich jnal^ i.t difficult to open the lock by any general or 

 common procefs. The general procefs for picking a lock, qf 

 • . -wljichthe key has not been feen, confifts in operating upon 

 thg.bpU byj a fmall bended inftru-raent or wire ; or elfe by en-. 

 .d^avp^ir'^ng^A discover the.pofition of the wards by an unper- 

 %,,..i -j.r., : . , .^Cfite;d,key,, ^;n the lace of wbiclVjfome foFt or plaftic matter is 



" ■ 'lodged. i4,ndJy^)^9n this fUualjlon is. once difqovered, it is not 



diJiicuU iff f}}e ayy^y (o much of the key as thall allow it i,Q 



p^fs,,,pr eUe._tQ >ip!f^C^, out of a number of Ikeleton keys, one, 



o^, whivh Ah.e;forn)i^i»^ll a^rajt of i|s pafRng through the lock. 



There are ijaf^nyJQpks fo fituated, as for exaqaple in the vef- 



t,rles of cljyr^lie.s.^nd other little frequeiited places, as to adr 



cpiit p/ thi|», fl9w operation ; but it niuft at Ihp faine time be 



allowed,. Uiat th^J.E'^g'ifli "market prefep^ locki; .of a nun^ber, 



»dj notjJffrr:-.iQl jdifii;reinit/-cpnflru.6tion';, »'.hich can . neither be picked nor 



,?T.»ii 10 i-jLij^jjj^ly^e^^ by ,tjhe prqcefs h^^e .roiqnti,o.^edj^ Nothing is, ropre 



9jij vd\"ii.'»9)fP.wqn»;,hpj(vfiyer, than jpr ,^ey5 19 l?e entrufled out of the 



«a 5di*i .4;-haft4s Qf, the pfliT^flferi w ^hP.hwSAd^ o^ cafually laid down 



"'^.i.^K'.iWW^'^i-iiifol tbftfe (jijJpUdwPanftcgp, l^ir figur,? n|^y iie,taj;en 



