THE JOHOEE SURVEY. 177 



map, on which is plotted the traverse, and also a great deal 

 of entirely new matter, including many topographical correc- 

 tions arising from the Survey made by the Staff and from 

 the exploration work carried out by Mr. Lake duriug 1891. 



Discussion. 



At the usual monthly meeting of the Engineering Sec- 

 tion of the above Society at University College, Bristol, 

 on Tuesda}^ evening, the adjourned discussion on the paper 

 on " Surveying in Unexplored Countries, — The Johore Sur- 

 vey," by Mr. A. Wharton Metcalfe, Assoc. M.Inst. C.E., was 

 resumed, Mr. Thos. Morgans, C.E., in the chair. The topo- 

 graphical and descriptive portions of the subject having 

 been fully dealt with on the previous occasion, the dis- 

 cussion turned on technicalities and resolved itself into a 

 consideration of recent improvements in surveying methods 

 and instruments. 



Mr. Metcalfe, at the request of the Chairman, then read a 

 brief supplementary paper on Tacheometry and Telemetry. 



The author, in opening, remarked that before a body of 

 engineers it was not necessary to define the theodolite or 

 level, or to go into the question of the elementary principles 

 underlying their construction, which were obvious enough ; 

 but that he would assume that all present were more or 

 less acquainted with the general construction of those 

 instruments. Tacheometry and telemetry might be con- 

 sidered as the art of measurement of distance by means of 

 telescopic observations on vertical graduated staves, or 

 staves of known length: as in distinction to the usual 

 methods of measurement by means of the chain, or by 

 angular observations and chain combined. Tacheometers 

 and telemeters were the instruments by which the above 

 purposes were best accomplished. It was obvious to any one 



