When it came to surveying the Canadian wilderness, what would have taken one day in Great Britain took at least three or four days in Canada. European surveying techniques at the time used a theodolite – an instrument used to measure distance and elevation by establishing a grid of fixed points. Such techniques, however, were less suited to the hostile Canadian weather and terrain conditions. In order to accurately measure swampy areas, for example, surveyors at times had to wait and revisit them after the water and soft ground froze. Unfortunately, this often meant that the theodolite also froze solid, rendering it unusable. In other areas, the dense canopy of forest was so thick that they were forced to work in darkness or by candlelight.