meters are only approximately accurate for
this purpose. So it was suggested that the two methods should be
combined: the aeroplane should endeavour to fly at a fixed height, and
the range-finders should, if possible, also make their calculations.
These methods cannot attain to the accuracy of wireless, but they were
found in practice to give fairly good results. They were not quickly or
generally adopted; many battery commanders continued to prefer the
reports of their trained ground observers to the indications given from
the air. When wireless machines were increased in number, artillery
observation from the air came into its own. In a report dated the 5th of
February 1915, Brigadier-General Stokes, commander of the 27th
Divisional Artillery, lays stress on the enormous advantages of
wireless. He says that the 116th Heavy Battery of the Royal Garrison
Artillery, which had at its disposal an aeroplane equipped with a lamp,
had succeeded in registering only three targets in fifteen days, whereas
the 130th Howitzer Battery, which had a share in the services of a
wireless aeroplane, had registered eight targets in seven days. The
disadvantages of the older and cruder method are many; a thin mist which
does not prevent the aeroplane from observing the target is enough to
prevent signalling to the battery; the lamp is difficult to use on a
rough day, and difficult to read against the sun; the aeroplane has to
be kept under continual observation by the battery. To get better value
out of our artillery, the general concludes, the wireless service must
be largely increased.

Reconnaissance from the air was much impeded, during the second half of
October, by low clouds and bad weather, but enough was observed to give
some forecast of the tremendous attack that was impending. The Germans
outnumbered the British three or four times, and threw their whole
weight, now against one part, and now against another, of the thin line
of infantry fighting in mud and water. Those who would judge the battle
will find no escape from the dilemma; either the British defence,
maintained for thirty-four days, from the 19th of October to the 21st of
November, against an army which esteemed itself the best army in the
world, must be given a high and honourable place among the great
military achievements of history, or the German army was disgraced by
its defeat. But the German army was a good army, and was not disgraced.
The Germans themselves res