Wood began by pointing out that seals could be taught almost anything that dogs could. A collar with a steel wire attached to a large hollow ball of rubber painted scarlet and dragged along on the surface would enable the sub-chaser to follow the seal! A. G. Webster, professor of physics at Clark University, protested against wasting the board’s time with such a silly suggestion, and another member said you couldn’t train an animal to do anything it had no natural instinct for. Wood countered by asking, “How about fox hounds following a bag of anise seed?” and suggested that it would do no harm to consult a professional seal-trainer, who would be the one best qualified to decide whether the suggestion was worth trying.
Sims took the idea over to London, and within a month the Admiralty was conducting experiments with seals, on a lake in Wales, admitting subsequently that the idea had come through the United States naval attaché in London. They found that seals could be trained to hunt out and follow the sound of a submarine’s propeller, and perhaps the odors from the oil and exhausts. The experiments were commenced with an electrical “buzzer”, and the hungry seal was rewarded with a fresh fish as soon as he located or followed it. In experiments with their own submarines, they had what Dr. Wood characterized as “considerable success”.
The “water bloodhounds” never trailed or caught any German U-boats, however, and as a would-be honest biographer I am compelled to say that the “considerable success” attributed by Dr. Wood to his trained seals was not a determinate factor in marine warfare. The seals had been muzzled to discourage independent fishing expeditions of their own, but one of the difficulties encountered was that they had a tendency to run off after schools of herring anyway — just as the bloodhound abandons Eliza or a convict to go off chasing rabbits. Other difficulties were that the seals not infrequently followed
It was after Wood had his major’s commission and was working with the Bureau of Inventions in Paris, in co-operation with all the Allies, that he conceived what has since been variously called the “spider shell”, the “spaghetti shell”, the “piano-wire shell”, and the “parachute shell”. It perhaps happily combines, as I see it, the two paradoxical categories of his war inventions. It is certainly fantastic, yet it must be pragmatically sound, since the British were reported to be reviving and using it in the air defense of London in 1940 — and international press services were attributing its origin to “Professor R. W. Wood, Johns Hopkins University physicist”.
Here’s what Wood says about it.
In discussing defense against hostile aircraft with a number of officers of the French air force at one of the aerodromes, in November, 1917, I suggested that experiments be made with shells containing a coil of steel piano wire — the shells to be constructed like the “parachute bomb” in pyrotechnics. One end of the coil was to be attached to the base of the shell and the other to a small silk parachute packed in the nose. On explosion the base would be driven downward, unwinding the coil of wire, while the parachute would open and drift along with the long strand of wire dangling below, like the spider that spins a long thread into the breeze, and then floats away carried by his thread. I also suggested this at one of the meetings of the Bureau of Inventions in Paris, calling it the “spider shell”, but nothing appears to have been done with the idea at the time. After the war I alluded to it in a number of public lectures on the relation of scientific research to warfare. Several paper patents appear to have been taken out by various parties in the interval between the two world wars. According to press accounts the wire strands used in the present war were not provided with parachutes and would fall rapidly.