900 
£5XiIA>"CE Jlf TUl; roiiT 
men??fwV the move- 
ment of which was from east to west. The part where the 
immersiouwp to take place was consequentljf .a few minutes 
pricr to the immersion, much more brightly illumiued than 
the western edges. Is this phenomenon to' be attributed to 
*0 » Partial accumulation 
'''^<1° *’ •■'’^sorbing a considerable part of the 
ot the earth ^ It a similar cause, in the perigee of central 
eclipses, sometimes reudei's the disc invisibl? may it not 
happen also that only a small portion of the inooni seei^ 
a disc, irregularly formed, and of which difierent parts 
were successively enlightened? ^ 
On the morni'ng of the 30th of March we doubled Punta 
Gigantes, and made for the Boca Chiea, the %esS? 
entrance of the port of Carthagena. Prom' thenS the 
foSn'^'tnd auf to toe anchorage near the 
town and although we took a wactico to pilot us we 
repeatedly touched on the sandbanks. On^ landb; I 
learned, with great satisfaction, that the e5pedition°kp- 
^fM Rdalt^'^ under kedireeJn 
ot M. Pidalgo had not yet put to sea. This circumstance 
not only enabled me to ascertain the astronomical position 
of several towns on the shore, which had served me k 
^“the toronometrically the longitude 
I'lanos and the Ormoeo, but also seiwed to guide me 
with respect to the future direction of my jouniey to Pera 
rhe passage from Carthagena to Porto Bello, and tharof 
(he isthmus by the Eio Chagres and Cruces, are alike short 
and easy; but it was to be feared, that we might stay long 
at Panama before we found an opportunity of koceedmg to 
f-ruayaquil, and in that case the voyage on the keihe woMd 
be extremely lingering, as we shoutd have to sail akinst 
contrary winds and currents. I relinquished with ^o-ret 
he hope of levelling by the barometer, the mountainfof 
the istlimiis, though it would then have been dMt to 
have beSiffectod measuremkts 
Cohimbl Sf i ^ iT Mexico and 
Columbia, we should remain in ignorance of the heio-ht of 
the ridge which divides the waters in the isthmus® The 
persons we consulted all agreed that the journey by land 
