374 Proceedings of the Royal Society of Edinburgh. [Sess. 
XXIII. — An Investigation into the Effects of Errors in Surveying. 
By Henry Briggs, B.Sc., A.R.S.M. Communicated by Principal 
A. P. Laurie. 
(MS. received January 7, 1911. Read February 6, 1911.) 
(Abstract.) 
(Paper appears in Transactions B.S.E., 1911.) 
The paper discusses the effects of errors in linear and angular measurements 
on the accuracy of surveys, and is divided into six sections, thus : — 
Section I. The Sum of Vector Errors. 
Section II. The Average Error due to Imperfect Centring. 
Section III. The Relative Effects of Errors in Centrum and those of 
Sighting and Reading. 
Section IV. The Propagation of Errors in Traversing. 
Section V. The Propagation of Errors in Minor Triangulation. 
Section VI. A Summary of Results. 
Under the first section a simple mode of summing vector errors is 
established, which is made use of throughout the rest of the paper, and 
particularly in studying the accuracy of triangulation in transmitting 
distance. Special stress is laid on the practical conclusions to be drawn 
from the inquiry, and curves and diagrams are given illustrating the effects 
of error in different branches of surveying. 
The last section is divided into two parts. In the first of these are 
placed the results, eight in number, which may be considered as already 
recognised by surveyors, and in the second are given twelve results which 
the author believes to be new. 
