“I should say certainly not the latter; probably it was a small saloon—but it might have been a coupé. I couldn’t really be sure.” “Could you swear it was not an open car with the hood up?” “Not swear, no—I didn’t notice particularly enough; but I have a very strong impression that it was not.” With that strong impression Poole had to be satisfied; confirming, as it did, the testimony of the Park-keeper, Blossom, it seemed to eliminate Inez Fratten’s open Vesper. While the question was before him Poole thought he should have a look at the car, so he went round to Queen Anne’s Gate and, with Inez’s permission, had it run out of the garage. One glance was enough; it was a low, distinctly “sporting” model, with a hood which, when lifted, fitted closely over the head of the driver. Poole felt sure that Mr. Smythe could not possibly have gained the impression of a small saloon or coupé from this little whippet. He heaved a sigh of relief, thanked the chauffeur and walked away. His next visit was to a gunsmith, a man from whom he bought his own cartridges and whom he knew to be an expert in his own line. Poole showed him the rubber bullet and asked him to suggest a weapon that might have fired it. “We had an idea it might be a powerful catapult,” he said. The gunsmith examined it closely, using a magnifying eye-glass. After nearly three minutes of scrutiny he removed the glass from his eye and handed it and the bullet to the detective. “It’s not been fired from a rifled barrel; there’s no characteristic corkscrew grooving. On the other hand, there is a very faint longitudinal groove—look at it yourself—all along each side of the bullet. That suggests some running pressure along each side. I don’t see how a catapult would do that, but what about a cross-bow? The half-open barrel of a cross-bow would allow very slight expansion of the rubber in the upper half of the bullet; as the bullet lies in the open barrel, half of it appears above the wood or metal, whilst the lower half fits into the half barrel and may be ever so slightly compressed by it. When the bullet is forced along the barrel this pressure or friction in the bottom half and lack of it in the top half would be liable to cause a slight groove to appear all the way down on each side—like what you see on that bullet. That’s the solution that occurs to me, Mr. Poole; I should be interested to know sometime if it fits in with the facts.” On his way back to Scotland Yard, Poole called in at Dr. Vyle’s house and, showing him the bullet, asked whether, if fired from something like a cross-bow, it was capable of inflicting the injury which had caused Sir Garth’s death and of making just so much mark on the flesh as subsequent examination had revealed. The police-surgeon was intensely interested by Poole’s “exhibit”; he weighed it in his hand, pinched it, struck it against his own forehead and examined it minutely through his magnifying glass.