Ƙirƙirar wani nau'i mai mahimmanci na wannan jumla Welshman ya kasance da alhakin kammala ɓangaren Babban Trigonometric Survey na Indiya tare da arc meridian daga kudancin Indiya yana shimfiɗa arewa zuwa Nepal, nesa da kimanin kilomita 2400.
Tabbas, mafi rikitarwa na jumla shine "Welshman ya kasance yana da alhakin kammala sashin Babban Binciken Trigonometric na Indiya tare da arc na meridian daga kudancin Indiya yana fadada arewa zuwa Nepal, nesa da kimanin 2500 mmeters urvey William Lambton ya fara ne a 1806 kuma ya ɗauki shekaru da yawa. "