214 DISCOVERIES OF THE ENGLISH. 
the gun in his own custody, which, coming to the 
ears of the crew, very naturally gave rise to a 
mutiny. 
As Moore resided so long in this part of Africa 
in the capacity of factor, his account of the com- 
merce upon the river is perhaps the most valua- 
ble which we yet possess. 
The Gambia is navigable for sloops six hundred 
miles from its mouth, to the falls of Barraconda. 
To that point also the tide ascends, which he re- 
marks is higher than in any other river with which 
he is acquainted. The lower parts are flat and 
woody ; but the upper rise into hills of consider- 
able height, composed of iron-stone. The value 
of European goods is expressed by bars, an ima- 
ginary denomination, expressing a certain quan- 
tity of each species of commodity. A pound of 
fringe, two pounds of gunpowder, an ounce of 
silver, and a hundred gun flints, are each equal 
to a bar. There are certain articles called " the 
heads of the goods," being those alone for which 
there exists at all times a sure demand. These 
" heads" are spread-eagle dollars, crystal beads, 
iron bars, brass pans, and arrangoes. Into the 
price of every slave, there must enter a cer- 
tain number of heads. The articles received in 
return are chiefly gold, ivory, bees-wax, and, 
above all, slaves. The gold is of good quality, 
finer than sterling j it is brought in small bars. 
