for a 4.2, and next that _Koenigsberg_ was a much larger target than either _Severn_ or _Mersey_. _Koenigsberg_ was probably aground, and therefore showing from three to four feet more of her side than she would at sea. Monitors are a craft with a very, very low freeboard, with a comparatively small central house built up amidships. As a point-blank target _Koenigsberg_ would probably be more than twice the superficial area that either _Mersey_ or _Severn_ would present. The contrast between them as virtual targets, that is, the target that would be presented to the shell as it descended from a height upon the ship, would not, of course, be so great, because the monitors were each of them wider than the German cruiser, but even as a virtual target the _Koenigsberg_ was much more favourable for the British guns. But the master difficulty of the situation was for the men on the spot, without previous experience of indirect fire, and unaided apparently by any advice from headquarters as to the result of service experiments elsewhere, to extemporize all the processes for finding and keeping the range of a target invisible from the ship. The two essential elements in these processes were (1) for the observer in the aeroplane to note where each shot fell, and (2) to _inform the ship that fired it_ exactly what the position of the impact was, whether to the right or to the left, over or short, and an approximate measurement in yards of its distance from the target. No one of those concerned had ever engaged in any similar operation. The aviators had not only never carried observers to spot naval gunfire, they had none of them ever even flown in the tropics, where the conditions of flight differ altogether from those in more temperate zones. The observers were even more new to the work than the aviators. Apparently some of them had never been in flying machines before. They not only had to learn the elements of spotting, they had to become familiar with the means of sending communications. There seems at one time to have been considerable doubt as to the best means to employ for communication. The means would have to include not only a system of sending messages, whether by wireless, by lights flashing a Morse code or otherwise, but the production of a code as well. When these points were settled, the preliminary practices of Mafia Island gave what appeared to be sufficient experience to show that right principles were being followed. Only when this practice had given satisfactory results was the first attempt of July 6th made.