Volumetric methods are more expeditious and require less apparatus.
In 1750 he published at Cambridge a work of some eighty pages entitled A Treatise of Artificial Magnets, in which is shown an easy and expeditious method of making them superior to the best natural ones.
Instead of shading lines following the greatest slopes, lines following the contours and varying in their thickness and in their intervals apart, according to the slope of the ground to be represented, may be employed' This method affords a ready and expeditious means of sketching the ground, if the draughtsman limits himself to characteristically indicating its features by what have been called " form lines."
The more expeditious method is of course to lay down turf, which should be free from weeds, and is cut usually in strips of i ft.
