752 



Transactions of the Society. 



"4 h. 3 V. 1. a." • and the corner square with four dots would be 

 the fifth horizontally and fifth vertically, to be marked " 5 h. 5 v. 1. a." 

 All the above-mentioned markings apply to the other three quarters 

 of the central block, with the exception that the left above becomes 



Fig. 72. 



::| I — 



~ I 



; 







left below, or right above, or right below, of course always counting 

 from the centre ; for instance, the square marked with a O near 

 the lower right-hand corner being the fifth horizontally and fourth 

 vertically to the right and below the centre, to be marked 

 " 5 h. 4 V. r. b." 



Having thus explained the reading of the central block,we may 

 take the one marked x in Fig. 71, which we will now assume 

 Fig. 72 to represent, the small square with three dots would be the 

 44th horizontally and 43rd vertically, or, 44 h. 43 v. 1. a. 



The above expressions might be simplified, as Mr. Crisp has 

 51 4 , 43 Z 



suggested to me, into 



-^, and -— T) the numerator of the 

 or 44 



fraction always representing the vertical lines, and the denominator 

 the horizontal ones, and I and r being placed in the upper or 

 lower part of the fraction, according as the upper or lower, right 

 or left, quadrant of the finder is inteuded. 



Travel sing the finder in any direction from the centre, one 

 can go through only seven blocks and a haK — being in all only 

 seventy-five squares. After counting the squares once or twice, it is 

 wonderful how rapidly the figures designating the squares are 

 arrived at ; and if the foregoing description be clearly understood 

 the process is as short, simple, and certain as it can possibly be 

 without numbered squares. 



