1902.] A Portable Telemeter, or Range-finder. 357 



gave the most favourable results, I prefer to append to my paper the 

 results of two days upon which I had with me experienced indepen- 

 dent authorities, who were good enough to draw out and sign certifi- 

 cates of all the tests made. 



Copy of certificate of an ordinary day's work on a cloudy day, drawn 

 out and signed by Sir David Gill, K.C.B., H.M. Astronomer, Sir 

 John Ardagh, K.C.I.E., C.B., K.E., Lieut.-Colonel J. E. Edmonds, 

 RE. 



February 5, 1902, Royal Observatory, Cape of Good Hope. 

 The following measures of distance were made from the roof of the 

 Koyal Observatory, Cape Town, on February 5, at 4 p.m., on a dull 

 clay, clear atmosphere, light S. breeze, without tripod stand, by Pro- 

 fessor G. Forbes. The distances recorded were in each case read 

 independently off the screw head by Mr. V. Lowinger, of the Observa- 

 tory. The actual distances of these points are based on actual 

 survey. 



• 



Distance 

 in yards. 



Observed. 



Computed — 

 observed.* 







yards. 



yards. 





1859 



1868 



-9 





3036 



3127 



-91 



North-east corner cottages between Ob- 



852 



857 



-5 



servatory and Salt River 









Chimney of Cement Works, Salt Eiver . . 



1432 



1440 



-8 



Chimney in Salt River Railway Works . . 



1711 



1748 



-37 



Dutch Reformed Church steeple, Wood- 



2740 



2920 



-180 



stockf 









* [The errors being all negative and increasing with the distance is due to the 

 ibinocular having had its scale index set inaccurately.] 

 f The steeple was at the time enveloped in a dust storm. 



Copy of certificate of an ordinary day's work on a very windy and 

 dusty day, drawn out and signed by Sir David Gill, K.C.B., 

 H.M. Astronomer. 



The following measures of distance were made from the roof of the 

 Koyal Observatory, Cape Town, on February 6, at 11 A.M., bright 

 ■clear day, strong S. wind, by Professor G. Forbes. The distances 

 recorded were in each case read independently off the screw head by 

 Mr. V. Lowinger, of the Observatory. The distances of the points are 

 based on actual survey. 



