PRESIDENT S ADDRESS. CX111. 



the past year was the journey from Pekin to Paris in a motor car 

 through countless difficulties, which shows the wonderful develop- 

 ment of these machines in the past few years. The journey was 

 made in 62 days at a rate of about 121 miles a day. The 

 Chinese magic mirror, when a beam of sunlight is reflected from 

 it on to a sheet or other light-coloured surface, shows in the 

 white patch of light the pattern raised on the back of the mirror 

 in casting it. That this is due to a slight deformation of the 

 reflecting surface is confirmed by an accidental observation that, 

 when a pane of glass was held by a pneumatic india-rubber 

 holder and a film of silver deposited on it, the reflected image 

 similarly showed rings where it was bent in a very minute 

 degree by the suction of the holder. I have never had anything 

 personally to do with boreholes, but have always felt that it must 

 be an exceedingly difficult matter to keep them vertical. It was, 

 therefore, with interest that I read the results of measurement 

 in 22 boreholes in the Rand in South Africa. The average 

 horizontal displacement amounted to no less than 440 feet in a 

 depth of 2,000 feet, the greatest being 2,370 feet in a borehole 

 4,200 feet deep, and the least 160 feet in a borehole of 2,000 feet. 

 In the first case the bottom of the hole, so far from being exactly 

 below the top, would be in a direction making more than 

 45 degrees with the vertical, and the actual depth below the 

 surface of the earth would be, I presume, not more than 

 2,000 feet, instead of 4,200, the nominal depth. The thickness 

 of strata calculated from this borehole would thus have to be 

 reduced by more than half. It reminds one of the enormously 

 exaggerated depths which were formerly recorded in soundings, 

 from the line being dragged far from the vertical position by 

 currents during its descent. In a German publication attention 

 is called to an Arabic book of the 1 3th century, where a compass 

 is described, made by rubbing a steel needle on a natural 

 lodestone and fixing it on a wooden fish. This, when floated on 

 water, always points to the north, and is the earliest known 

 reference to the compass, though it is not treated as a new 

 discovery. A movement has been set on foot to provide 



