xii INTRODUCTION. 
recommended, that triplicates at least be kept of all the journals, and that each 
person carry about with him a brief abstract of his observations, in order that, 
in the event of any accident befalling his journals, he may still preserve the ab- 
stract to refresh his memory. 
Finally, in all your proceedings, you are to be particularly mindful of the 
health of the officers and men placed under your orders; to this end it will 
be adviseable to avoid, as much as possible, passing the night in the neighbour- 
hood of the mangrove swamps, which are said to abound on the banks of the 
. lower part of the river; you will prevent, as far as may be practicable, their 
exposure to the sun in the middle part of the day, as well as to heavy rains, 
and never permit them to sleep at night in the open air, but under an awning 
to protect them from the dews, which are always destructive of health in a 
tropical climate. 
You are to spare the people as much as possible, from long and severe 
exertion, and make use of the sails instead of sweeps or oars, whenever it can be 
done; considering a moderate rate of progress up the river with the former, as 
preferable to a rapid one, at the expense of the health of the men by the latter ; 
bearing in mind, that a moderate progress will afford better opportunities of 
acquiring knowledge in all departments of physical science, than a rapid one. 
But in the proper execution of all these matters, and the other important duties 
committed to your superintendance, my Lords Commissioners of the Admiralty ; 
rely on your judgment, discretion, and zeal; not doubting that you will use 
your best endeavours to execute all and every part of this interesting and im- 
portant mission, in such a manner as will afford full satisfaction to the public, 
as well as to the Lordships. 
By command of their Lordships. 
(Signed ) Joun Barrow. 
It may not, perhaps, be too much to say, that there never 
was, in this or in any other country, an expedition of dis- 
covery sent out with better prospects or more flattering 
hopes of success, than the one in question; whether it be 
considered a5 to the talents and zeal of the persons se- 
lected to carry the objects of the voyage into execution, or 
ihe preparations that were made for rendering the means. 
of executing it efficient, and for the health and comfort 
