The Shop Window Murders. Vernon Loder

He came in, and greeted the detective briefly. Devenish saw that he was an alert and handsome young man of about thirty, rather of a military cut, and obviously intelligent.

      ‘I was up on the roof just now, sir,’ the detective told him. ‘There were tracks that made me rather wonder if a machine had landed there lately.’

      ‘This is a pretty filthy business, inspector,’ said Mr Cane in reply. ‘Hardly bargained for a Wild-West shooting here. But what was that you said? A machine landed on the roof? Most unlikely, I should say. We had enough of that sort of thing a month ago.’

      ‘A certain amount of trouble, but also a good deal of advertisement, sir! I should like to have a list of purchasers of the “Mander Hopper”.

      ‘The first purchasers. But suppose they had been resold?’

      ‘No doubt we could trace them, said Devenish, offering his case to the young man, who took a cigarette and lit up.

      ‘I suppose you could. I’ll get you a list.’

      ‘Are these heavy machines?’

      ‘Yes, they are heavier than machines would be which were not fitted with the gyrocopter device, inspector.’

      Devenish approached a machine which was ready for flight. ‘The tyres on the landing wheels are naturally wider when the machine rests on them than when they are removed,’ he said.

      Cane grinned. ‘That is what “Punch” would call “another glimpse of the obvious”, inspector. I might even go further, and suggest that, at the moment when a machine lands, the impact makes the track even wider than that!’

      ‘Quite what I thought, sir,’ replied Devenish innocently. ‘Now could we get one of the wheels to make some sort of track here?’

      Cane thought it over. ‘I might chalk the treads of the two tyres, and we could push the ’bus a bit along the floor, if that is any good to you.’

      ‘Splendid, sir. While you are doing that, I might be looking at your books, and taking down some of the names of purchasers of these machines.’

      ‘Come to my office in the corner there. You’ll find pens and paper, while I get the books out of the safe.’

      There had been perhaps fifty purchasers of the ‘Mander Hopper’ since it had been put on the market, or rather, there had been promise of delivery of that number of machines. Devenish took down the names and addresses, and had completed his list when Cane called to him.

      ‘Palaver set, inspector.’

      Between them, they pushed a machine along the floor, and the inspector not only measured the whitened track made by the tyres, but also the width of the treads pressed out by the weight above.

      ‘That will do nicely, sir,’ he said when he had finished. ‘Now I want to ask you a question about Mr Mander. He was interested in machines and aerodynamics, wasn’t he? I saw some sort of a laboratory, or workshop, above.’

      Cane laughed a little. ‘He did tinker a bit, I believe; but I really know nothing about it. He said he always gave full charge of a department to a man, and never interfered.’

      ‘But who invented the machine here that is called by his name?’

      ‘It is assumed that he did.’

      ‘Well, didn’t he?’

      ‘Can’t say. He patented it, I know. I was only once up in his workshop, and he didn’t like that much. What I saw there of the jobs he did struck me as elementary. A fellow who invented this had to be a swell at other things than mechanics.’

      Devenish’s eyes lit up. ‘You mean that he did not seem to you capable enough?’

      Cane nodded. ‘I mean that, when I had to talk to customers once or twice before him, he never said a word. Can you imagine any chap who could invent a perfect gyrocopter standing mum while you were fiddling with his subject? I can’t! I know inventors. Perfect pests, poor devils, and ready to jaw your head off! That is about the only satisfaction they get out of their inventions.’

      ‘But someone must have invented it?’

      ‘Obvious again. But isn’t there just a hint that the man who did might have been on his uppers, and beam-ends, and so on, and been told he could get a purchaser if he kept his mouth shut?’

      ‘Ah!’ said Devenish heavily.

      Then he thanked Cane for his help, and left him to go on the roof again, where he made fresh measurements and comparisons, emerging half an hour later, and going towards the lift, when he met a man he had not seen before, a pompous stout man, with a bald head, who introduced himself as the assistant-manager.

      ‘The Stores are now completely cleared, inspector,’ he informed Devenish. ‘Is there any way in which I can help you?’

      The detective reflected, then: ‘Is this a private company?’ he asked.

      ‘No. Mr Mander was the sole proprietor.’

      ‘Really. But this is a very big organisation. Do you mean that he financed it himself?’

      ‘So far as I know. I can’t say.’

      The interview got no further than that, for a constable came hurrying up to say that Mr Melis, an Assistant-Commissioner from the Yard, was in Mr Mander’s private office, and wished to see the inspector.

       CHAPTER IV

      THE staff had been turned out of Mr Mander’s room, and Mr Melis sat there in state, a cigarette between his long fingers, and his brown, humorous eyes fixed on Inspector Devenish’s face.

      ‘Doesn’t seem anything very tangible to take hold of so far, inspector,’ he was murmuring in an agreeable voice, ‘unless it is this business of the gyrocopter.’

      ‘What interests me more, sir,’ replied Devenish, ‘is the person who financed Mr Mander. I can’t make that out. He seems to have sprung up suddenly from nowhere, and even if he was a genius at this sort of thing, where did he get the money?’

      ‘Ah, that,’ said the assistant-commissioner, laying down his cigarette and smiling very faintly at some thought, ‘that is not so difficult as it looks. But being simple—at least I think it is, if gossip counts for anything—it does not interest me.’

      ‘Then you know, sir, who was behind him?’

      ‘I don’t exactly know, inspector; but one picks up things as one moves about; doesn’t exactly know if they are authentic, you see, but wonders if they may not be.’

      ‘Then, sir, if I may ask, who do you think, or wonder, may have been behind here?’

      Mr Melis began to toy with his cigarette again. ‘Frankly, Dame Rumour hints that Mrs Peden-Hythe was the goddess from the machine. She was the widow of that fellow, you know, who had the shipping company in Buenos Ayres.’

      ‘About forty-three, and rather handsome,’ said Devenish. ‘I have seen her photographs in the society papers. But why pick on Mander, sir?’

      Melis shrugged. ‘Mander was managing-clerk to the country solicitors at Volbury, where her place, Parston Court, is. Fancy is an errant thing, inspector.’

      ‘So it is, sir,’ replied Devenish. ‘That does put another face on it. But you spoke of the gyrocopter, sir, what is your view about that?’

      ‘Mine? I thought it was yours. The wide track and the narrow track, you know. It quite seemed to me that you regarded the idea of the machine having landed on the roof last night as more or less—shall we say—a plant?’

      Devenish thought that over. ‘You see, sir, it looks like an inside job. Someone who knew Mander and the place thoroughly. But I wouldn’t bank on it all the same. Naturally, it did strike