JAMES CLARK ROSS 255 
manding the confidence of the Admiralty to such a degree 
that his orders were qualified by a general discretion 
which left him wide freedom of action. The instruc- 
tions given on September 16th, 1839, defined the pur- 
pose, order and duration of the cruise. It is of interest 
to compare them with the instructions given to the com- 
manders of the other expeditions, and we accordingly 
quote their principal clauses: 
“ Whereas, it has been represented to us that the 
science of magnetism may be essentially improved by an 
extensive series of observations made in high southern 
latitudes, and by a comparison of such observations with 
others made at certain fixed stations, and whereas prac- 
tical navigation must eventually derive important benefit 
from every improvement in that science, we have, in con- 
sideration of these objects, caused Her Majesty’s ships 
Erebus and Terror to be in all respects prepared for a 
voyage for carrying into complete execution the pur- 
poses above mentioned ; and from the experience we have 
had of your abilities, zeal, and good conduct, we have 
thought fit to entrust you with the command of the ex- 
pedition, and to direct Commander Crozier, whom we 
have appointed to Her Majesty’s ship Terror, to follow 
your orders for his proceedings. 
“ You are therefore required and directed, as soon as 
both vessels shall be in all respects ready, to put to sea 
with them, and on your way to your ulterior destination, 
you will touch at the Island of Madeira, in order to 
obtain the sea-rates of the several chronometers with 
which each vessel has been supplied. From thence (but 
making a short series of observations at the Rock of St. 
Paul) you will make the best of your way to the Island 
of St. Helena, where you are to land the observers and 
