Not far from this bombarded coast is a summer resort town, where for many years a legend has existed that when in some future age England decayed and Germany came in, this would be the first landing-point.
An Englishman two or three years ago took it upon himself to find out how far this legend might have its base in any near invasion.

He looked up the record and found that all the leading summer hotels and strategic points were in the hands of Germans.

Then one day he quickly addressed his German waiter in his native tongue, demanding to know where his post was in that town in the event of hostilities.

Promptly the German replied, "Down at the schoolhouse!" Further investigation showed that every reservist had his allotted place before and after the landing, and his place in the civic organization to follow.

The Germans had also compiled lists of the people of property in that vicinity and exactly the character and amount of resources that could be commandeered from them.
If the Germans were free to map England, why should they not be free to map all its resources, individually as well as collectively?
I know a building in the heart of the London financial district that carries on its roof a Zeppelin-destroyer gun.