trigonometrically

Here I intersected various lofty distant summits seen on the 21st instant, and could thus connect the whole trigonometrically with back angles to Bindango, Mount Abundance, etc.

Journal of an Expedition into the Interior of Tropical Australia 2003

Russia refused her active co-operation in observing it, on the ground that oppositions of the minor planets were trigonometrically more useful, and financially far less costly; and her example was followed by Austria; while Italian astronomers limited their sphere of action to their own peninsula.

A Popular History of Astronomy During the Nineteenth Century Fourth Edition 1874

I had two important objects in view in ascending this hill; one being to determine its position trigonometrically as a point likely to be seen from the country to which I was going, where it might be useful to me in fixing other points; the other being to obtain a view of Port Phillip, and thus to connect my survey with that harbour.

Three Expeditions into the Interior of Eastern Australia, Volume 2 Thomas Mitchell 1823

Here I intersected various lofty distant summits seen on the 21st instant, and could thus connect the whole trigonometrically with back angles to Bindango, Mount

Journal of an Expedition into the Interior of Tropical Australia Thomas Mitchell 1823