MARKS AND HOW TO TAKE THEM. 5 



and the nearer object of small size, it will be necessary for the 

 observer to bring the smaller object in front of the centre or 

 either end of the larger object, in order to attain the necessary 

 precision. The objects most commonly used are of course 

 the most conspicuous which can be rendered available from 

 the position always remembering the foregoing cautions in 

 selection and consist of remarkable houses, chimneys, towers, 

 castles, churches, obelisks, windmills, trees, rocks, small islands, 

 points, headlands, hills, mountains, flagstaffs, beacons, or light- 

 houses. We have, up to the present time, been dealing with 

 theory, but, with the reader's permission, we will endeavour to 

 reduce our theory to practice, that is, as far as we are able to 

 do so on paper. 



For this purpose I have appended the accompanying small 

 chart, which will, I think, render my instructions sufficiently 

 clear to those unacquainted with the subject, whilst the ex- 

 perienced will, I trust, therein recognise the practical nature 

 of the instruction conveyed. This chart (fig. i) represents a 

 portion of the sea coast adjacent to the harbour of St. Peter 

 Port, Guernsey, with a set of marks and lines of sight in use 

 for finding a certain fishing-ground, on a sufficiently large scale 

 (four inches to a mile) to avoid confusion of lines. It is 

 required at half an hour before low water spring tides, direction 

 of the stream SW., wind NNE., to place a boat at a certain 

 position according to the following marks. The De Lancey 

 Obelisk, M, its own breadth open east of the breakwater light- 

 house, and the gap in the back-land touching the sharp edge 

 of the eastern cliff of the shingle bay. A is the line of direction 

 of the obelisk, M, passing outside the lighthouse on the break- 

 water, and forming the long mark ; B the line of direction given 

 by the gap in the back-land with the edge of the cliff, cutting 

 the line A at the boat's required position at F. After rounding 

 the breakwater, steer to the southward, getting on the mark A ; 

 keep on this line of direction until the mark B is discovered, 

 which is the cross mark, and shows you to have arrived at the 

 spot indicated. The killick, or mooring stone, must not be let 

 go here exactly on the spot, for when any amount of rope were 

 paid out, the boat would of course be much beyond the required 



