172 Report S.A.A. Advancement of Science. 



navigators can drive their ships at a speed of 26.5 statute miles an 

 hour with comparative confidence, even when neither sun, moon, or 

 stars are appearing." 



4. — Suggested Scheme for Permanent Magnetic Observatories 



IN South Africa. 



In offering any suggestions for remedying the lack of permanent 

 magnetic observatories in South Africa, several points have to be 

 taken into consideration. In the first place, the size of the region 

 demands that several observatories be founded. Secondly, the posi- 

 tion of these must be chosen in such a way that their usefulness 

 will not be destroyed at a later period by the magnetic fields due to 

 the use of electricity for lighting or for locomotion. This latter 

 consideration demands that no observatory be founded within a 

 distance less than 10 miles of any town which may have electric trams 

 within the next fifty years. Two such stations should be established 

 in the Cape Colony, one at Matjesfontein, the other at Lovedale, 

 one at Bloemfontein, one at Bulawayo, and one in Natal, somewhere 

 on the coast. In addition to the magnetic instruments, instruments 

 for the regular record of atmosphere electricity phenomena should be 

 provided. 



The cost per station would be about ;^3,ooo ; and each station 

 except Matjesfontein would require an observer capable of taking 

 absolute measurement of the various magnetic elements. 



The photographic records might be sent to a central office, just 

 as meteorological records are at present ; there the work of reduction 

 could be carried out. The establishment of observatories is of no 

 value if the observations ore not reduced and published as quickly as 

 possible. Such an arrangement as this would ensure that. An 

 additional advantage of such a central office would be to carry out 

 systematic comparisons with the different instruments of the various 

 observatories, thus ensuring comparability. The advantage of having 

 a number of such observatories spread at different heights over such 

 a large surface would be incalculable ; many of the outstanding 

 problems in magnetism and atmospheric electricity could be attacked 

 in a rational manner. 



