On Civiltoday.com, find the article summary about 'Tacheometric Surveying'. From this summary, explain what Tacheometry is, describe the primary method used to obtain distances, and identify the name of the instrument mentioned, even if the name is incomplete. Provide these details in your answer.
Navigate to 'http://civiltoday.com/' Locate the article summary titled 'Tacheometric Surveying- Methods, Detail Procedures' on the homepage. Extract the definition of Tacheometry from the summary. Identify the primary method used for obtaining horizontal and vertical distances from the summary. Identify the name of the instrument mentioned in the summary. Synthesize this information into a concise answer.
The definition of Tacheometry is stated as: 'a branch of angular surveying in which the horizontal and vertical distances are obtained by optical means as opposed to the ordinary process of chain and tape.' The primary method for obtaining horizontal and vertical distances is identified as 'optical means'. The instrument mentioned is identified by its initial letters 'he', acknowledging that the full name is truncated in the summary. All information is sourced directly from the 'Tacheometric Surveying- Methods, Detail Procedures' article summary visible on the Civiltoday.com homepage.