600 REPORT—1883. 
points are his minute details of the alterations in the course, and especially in the 
mouths, of the Athabasca and Peace rivers, which at the point of junction with 
the Slave river at the western extremity of Lake Athabasca now form vast deltas 
of sedimentary land, available for cultivation in a region elsewhere almost entirely 
wanting vegetable earth. The extremely variable hydrographic conditions are 
owing to an abnormal intercommunication between the three great watercourses 
above named, so that an excess of supply from the catchment basin of any one of 
them is passed over to the others. The various causes and stages of formation of 
new land, with the consequent development of vegetation &c., are fully explained ; 
and the author entertains great hope (though there can be no absolute certainty on 
the point) that the vast reclaimed area will remain in its present condition. 
In discussing the Indian tribes he refers to their great diminution from the 
consequences of an excessive destruction of animals available for food. The whole 
population of the district, including red-skins, half-castes, and whites, was in 1879 
only 2,268. 
An historic sketch and statistical and meteorological tables were given in this 
memoir, which with its accompanying map has been translated and published in 
the Proceedings of the Royal Geographical Society for November 1883. 
