(iv) =Firing from Cover.=--This instruction can be practised on miniature ranges, according to the rules laid down in Sec. 31, para. 4, with cover improvised by the use of sandbags, etc. Care must be taken to see that the firing positions are correctly adapted to different forms of cover. The need for keeping the eye fixed on the target when firing from cover can be illustrated on the Target by the use of scenery and disappearing and crossing figures representing men at different distances. The correct and incorrect method of using various kinds of cover can also be illustrated on the Target, together with faults such as firing over instead of round the side of cover when this is possible, undue exposure, and unnecessary movement. The Target can also be used with scenery and figures for lectures on the choice of cover and the advantages and disadvantages of different kinds of cover according to the instruction laid down in Sec. 31, para. 3 (ii) to (iv) inclusive, and para. 5. =4. Visual Training=--(i) =Discernment of Targets.=--Training can be carried out on the Target as described in Sec. 34 with different types of scenery and figures representing both men and bodies of troops in different formations at various ranges. The methods of instruction described in paras. 3 to 8 of this section, inclusive, can be carried out on the same principle as in training on the ground. (ii) =Effect of Background on Visibility.=--Figs. 55 and 56 illustrate object-lessons in the effect of background on the visibility of service targets. For instance, lying figures in front of the hedge to the left of the tree on the left of the white house in the foreground of Fig. 55 are hardly visible at close range in the open, while a khaki figure near the right edge of the dark wood to the right of the hills in Fig. 56 is distinct, though it represents a man 1,400 yards away, while the rest of a line of similar figures coloured grey extended to his right in front of the wood are invisible. It must be remembered that in photographic reproduction the visibility of the figures is exaggerated as compared with their visibility against the scenery when observed with the naked eye at 25 yards. (iii) Figures which are invisible to the naked eye against the scenic background of the Target can be made distinctly visible by holding a white piece of paper behind them to throw them into sharp relief. This object-lesson will illustrate the manner in which a sky-line or a sheet of water, for instance, affects the visibility of object seen against such backgrounds. The effect of movement on visibility has been dealt with in para. 3 (iii) of this section. (iv) =Use of Field-Glasses.=--This can be practised as described in Sec. 34, para. 6.