"A two-headed horse, Watson? How ridiculous. I am surprised that you have allowed yourself to be taken in by a hoax."
"You may laugh, Holmes, but I have seen the animal, and hundreds of others have flocked to see it, too, and it is real. Surely you can believe that Siamese twins are a possibility with horses."
"That I can, but not with a head at each end. That's not a horse. Not even in mythology is there a pushmepullyou kind of thing."
"Holmes, you once said 'When you have eliminated the impossible, whatever remains, however improbable, must be the truth.' I appeal to you to see the animal and you will be convinced by the evidence of your eyes."
"As you wish, Watson, except I don't need to see the animal. As you have already seen it I will simply use the evidence of your eyes, rather than mine, to reach a conclusion. Please tell me everything you saw but firstly let's give your strange horse a name. Let's call it Double-header."
"Double-header sounds fine. It can be seen at "Rowley Mile", the home of Lord Marmaduke Algernon Cholmondeley, the noted breeder of thoroughbreds. "Rowley Mile" has been the Cholmondeley family seat since the time of Charles II. It is an ancient manor with towers and battlements and there are many buildings, including stables and barns. It is like a tiny village surrounded by a stone wall about 5 feet high."
"How were you able to see Double-header?"
"The estate is not open to the public but a path runs within 50 yards of the wall and one could see and talk to the stablehands when they looked over the wall. Double-header could be seen moving behind the wall. He moved to the left and entered a stable. When he came out he went to the right into a blacksmith's shop, where, according to the stableboy, he was shod on all four legs."
"Every horse has four legs but only two fore-legs. Does Double-header have two fore-legs or four fore-legs, and does it have a total of four-legs or eight legs?"
"It's two heads, but not identical, two manes, two withers and its back could be seen above the wall but because of the height of the wall its legs could not be seen. What is quite clear, however, is that it moved in either direction without difficulty. Obviously, its brain coordinates its legs to move smoothly. A saddle was put on it and Lord Cholmondeley mounted. Double-header gave a buck and his lordship was thrown from the saddle. A jockey, wearing Lord Cholmondeley's distinctive purplish-blue racing silks, then mounted and rode it into the stable. When it reappeared, two stablehands each fed one of the heads with a handful of oats and a bucket of water. So that's it, Holmes, a freak of Nature. Are you not now convinced?"
"No! Not a bit of it, but what an ingenious bit of fun."
"You know how much I respect your powers of deduction so, please, tell me what you have deduced that I might share your mirth."
"I am surprised you have failed to deduce it already for when I mention the key thing you will instantly realise what has been done."
"I haven't a clue, Holmes. How did you work it out?"
"Elementary, my dear Watson. Here is my solution:
Double-header is not one animal but two horses standing alongside each other and harnessed head to tail. Horse-hair rugs are draped strategically over both animals to conceal the outline of each horse's rump. At a distance it looks like one animal.
The horses stand on a small flatcar for Lord Cholmondeley has installed a tiny railway line behind the wall. The height is carefully set to reveal just enough of the horses to bamboozle spectators. The stablehands wheel the flatcar between the stable on the left and the blacksmith's shop on the right. The rest is play-acting by Lord Cholmondeley and his staff, whom I guess are having great fun dreaming up more ways to befuddle their neighbours."
"Ye gods, Holmes, how could I be taken in by such a simple trick?"
"Descartes said 'I think, therefore I am.' You didn't think. If you had put Descartes before the horse you could have worked it out."