118 
ADEN. 
van-serai of Sheik Otliman, where we rested for the night, in 
order that we might pursue our route early on the following day 
before the heat should set in, which is here very oppressive. Our 
lodging was not particularly agreeable, on account of the building 
being hardly large enough to contain the party, but slight incon- 
veniences and difficulties only serve, by contrast, to give a zest 
to the enterprises of the traveller. 
Tuesday 10th. — At day-break we continued our route to Aden. 
As we approached the peninsula, we were much struck with the 
singular appearances which the sun put on as it rose. When it 
had risen about halfway above the horizon, its form somewhat 
resembled a castellated dome ; when three parts above the horizon, 
its shape appeared like that of a balloon, and at length the lower 
limb suddenly starting up from the horizon, it assumed the general 
form of a globe flattened at either axis. These singular changes 
may be attributed to the refraction produced by the different 
layers of atmosphere through which the sun was viewed in its 
progress. The same cause made our ship in the bay look as if it 
had been lifted out of the water, and her bare masts seemed to be 
crowded with sail ; a low rock also appeared to rise up like a 
vessel, and a projecting point of land to rest on no other foun- 
dation than the air ; the space between these objects and the 
horizon having a grey pellucid tinge very distinct from the 
darker colour of the sea. This deception of the atmosphere, as 
far as it affects the relative positions of the heavenly bodies with 
regard to the eye, is a subject which has been much attended to 
by astronomers, and tables have been constructed to obviate 
the errors it occasions, which are perhaps as accurate as the 
