Gps For Land Surveyors How Did Land Surveyors, Survey Before Electronics?

How did land surveyors, survey before electronics? - gps for land surveyors

I often wonder how on earth survey surveyor little old in remote reference? Got right? Could it be the accuracy of the present owners, if blocked? When the weather was overcast, it could continue to work? But it seems that we now have the GPS set, but it would be nice to know they exist, especially the gadgets of today and were too. Sincerely answer would be gratefully accepted.