( 203 ) 
IX. — Meteorological Journal, from the Mouth of 
the Bio de la Plata to the Coast of Chili^ 182^ ; 
with a Chart. 
By William Jameson, Esq, Surgeon. 
{Read l^th December 1823«) 
0. 
Dear Sir, Lima, bth August^ 
I HAVE enclosed a MS. chart of our track round Cape 
Horn. (See annexed Engraving.) The longitude, which is 
marked for noon, was generally determined with accuracy 
by means of three excellent chronometers entrusted to my 
care, and I have also marked the longitude, as estimated by 
dead reckoning, where there was any considerable devia- 
tion. In laying down the track, you will perceive I have 
adopted the method recommended by Captain Hall. 
In the passage round Cape Horn, the vicissitudes from 
heat to cold, and again from cold to heat, are very remark- 
able. At Kio de Janeiro, in February and March, ^the 
thermometer usually stands at 80° or 85°. In three weeks 
we reached the parallel of the Cape in Lat. 56° S., where, 
with frequent storms of hail, snow and sleet, we have the 
temperature of the air reduced to the freezing point. Ha- 
ving doubled the Cape, we make a direct northerly course, 
and in another fortnight we again enter a tropical climate. 
The change of temperature in the sea-water is no less re- 
markable. 
I have the honour to be, &c. 
William Jameson. 
To R. Jameson, Esq. 
President of the Wernerian Society^ 
