CHAP. VI.] RUNNING SURVEY 179 



At a distance of from 2 to 4 miles from the shore drop a 

 beacon abreast of some conspicuous object, called the First 

 Breastmark (1 B in Fig. 53), which should be if possible some 

 3 or 4 miles back from the coast. Note the time, and shape 

 a <;ourse parallel to the coact. Put over logs, and steam 

 about 10 miles down it, sounding and fixing with objects 

 selected, until the beacon gets indistinct from aloft, and you 

 are abreast the Second Breastmark. Stop, haul in logs, note 

 time^ and drop Beacon II, During the run down the coast, 

 three primary objects and other secondary ones have been 

 selected and named, and on arriving at II. a Provisional 

 Breastmark, 10 miles or so ahead, must be selected, and also 

 the middle Primary Point of the next fleet. 



At II. simultaneous angles are taken between I., the First 

 Breastmark, A, B, C, Primary Marks, Second Breastmark, 

 Provisional Breastmark, and Middle Primary of Fleet III. The 

 secondary objects are next taken, using any of the above- 

 mentioned points which are most conveniently situated as 

 regards distance, so that any small change of position of the 

 ship shall make the smallest possible alteration in the angle. 

 Each officer is told off to a primary object and some secondary 

 ones, and is responsible that his secondary objects are taken 

 to a suitable zero. 



On taking angles, the bearing of Beacon II. (Avhich will be 

 as close to as is safe), and also its distance by elevation of its 

 staff, is noted. Take also compass bearing of Breastmark I. 

 as a check. 



Now steam straight out for, say, a mile or so. Turn ship's 

 head ready for the run back, and stop. Take simultaneous 

 angles as before, at Corner II., Breastmark I. being observed 

 instead of Beacon I., which there is no occasion to look for. 



Note time and bearing of Beacon II., put over logs, and 

 shape a course parallel to first run. 



Run back about one-third of the distance. Stop, and make 

 Intermediate Fix I. 



When I. is on the same bearing as was II. when logs were 

 put over, note time, read logs, and stop for the Corner Fix I. 



Then lun into L, take angles, etc., as at II., and pick up 

 Beacon I. 



The primaries and breastmark can be plotted roughly fron? 



12—2 



