Of course, without any definite information on the subject it is impossible to say exactly what he was doing in Spain. But I am sure that it is far more likely he had landed from a German submarine on the coast of Spain and that he was posing as an American mining engineer for a particular purpose.
I told certain people in Spain about Bode and of his intention to visit the mining districts of Spain where numbers of men are employed. Bode must have suspected that I had given information about him, for Hall and I received several postcards of a threatening character, evidently from him.
My cables to and from the State Department passed through our legation at Copenhagen, and, of course, if the Germans knew our cipher these messages were read by them. On special occasions I made use of a super-cipher the key to which I kept in a safe in my bedroom and which only one secretary could use. The files of cipher cables sent and received were kept in a large safe in the Embassy. But before leaving Germany, knowing the Germans as I did, and particularly what they had done in other countries and to other diplomats, knowing how easy it would be for them to burglarise the safe after we left, when the Spaniards and Dutch were out of the building at night, I tossed all these despatches as well as the code books into a big furnace fire. Commander Gherardi and Secretary Hugh Wilson stood by and personally saw that the last scrap was burned. Of course, copies of all the cables are in the State Department.
German spies are adepts at opening bags, steaming letters—all the old tricks. The easiest way to baffle them is to write nothing that cannot be published to the world.
For a long time after the beginning of war I was too busy to write the weekly report of official gossip usually sent home by diplomats. I suppose the Germans searched our courier bags for such a report vainly. Anyway, its absence finally got on the nerves of Zimmermann so much that one day he blurted out, "Don't you ever write reports to your Government?"
Sealed letters are opened by spies as follows:
by inserting a pencil or small round object in the envelope, steamed a little, if necessary; the envelope is opened at the end flap and the contents pulled out without disturbing the seal, the contents are then read, put in their place again, the end flap re-inserted, a little gum used and the envelope is as intact as before.
The only safe way to seal an envelope is thus:
