A Riddle in Bronze

to be safe enough, and this might be my only chance to gain the knowledge I sought before Roberta or Mrs Fairacre packed the equipment away.
I decided to risk it, and within seconds I was on my feet, heading for the hall. I stopped in the doorway, listened carefully for the sound of voices or approaching footsteps, then hurried along the corridor towards the front door.

Chapter 6
I moved quickly along the hall, making for the shadows at the front door where the bags were still present. I confess my heart was in my mouth as I crouched to inspect the contents, for I am not one given to snooping or sneaking. My usual thrills came from checking the totals in a double-entry ledger to discover my sums were accurate and without error, not poking through someone else's belongings.
Under the circumstances, though, I felt it justified. If nobody would reveal the truth to me, I would uncover it for myself.
Opening the straps on the nearest haversack, I lifted the flap and peered inside. The first item to meet my eyes was a metal cage of around six inches in height, with a screw fitting on the underside. It looked like a lantern, although there was no glass, and instead of a wick I saw a bronze cylinder within, suspended from fine wires like a spider in its web. I recognised the cylinder, for I had seen numerous examples in the professor's study the day before, but unlike those specimens this one had been blasted open at one end. The rounded metal cap was split, with fragments peeled back like a ring of petals, and I could see right inside to the blackened metal interior. Was it an explosive device which had gone off prematurely, leading to the professor's dazed state?
Some of the wires holding the cylinder were broken, snapped apart by the same force that had damaged the device, and as I studied the curious setup I itched to pick it up for a closer look. I glanced down the hallway, but the house was as quiet as the grave and there was no sign of Roberta, the housekeeper, or the maid.
So, I lifted the cage from the haversack and set it aside. Underneath there was a wad of netting, carefully folded. It was cold to the touch, and I realised it was made from metal wire, drawn to an unnatural thinness. I laid this aside also, and beneath that I saw half a dozen metal discs of the type the professor had shown me the day before. I picked one up, turning it over, but there was nothing unusual about it.
There was nothing else, so I replaced the contents and turned my attention to the second bag. Engrossed, I was reaching for the flap when I heard a sharp voice behind me.
"Mr Jones? What are you doing?"
I stood up fast, as though my legs were on springs, and turned a ghastly, guilty look on Mrs Fairacre. "The professor asked me to fetch his bag," I said quickly, for it was the first thing that came into my head.
The housekeeper's face softened at the mention of her employer. "The professor is fast asleep. You would know this, if you were still watching over him." She eyed the bags at my feet, which were both closed, and I was relieved I'd yet to begin my inspection of the second. "And in any case, those are Miss Roberta's things."
"The professor seemed a little confused," I said lamely. "I, er… I'll return to him immediately."
"No, I will mind the professor. You are to join Miss Twickham in the workshop, where she requires your assistance." Mrs Fairacre pointed down the hall. "Go past the stairs and take the second door on the right."
I set off, relieved I'd escaped further questioning. The housekeeper was no fool, and I was certain she'd have interrogated me further if she weren't so concerned for the professor's well-being. I got the impression that Mrs Fairacre was fond of the professor, but there was nothing improper in that. The previous evening, over dinner, Roberta told me her mother had passed some years ago, after a long illness. If Mrs Fairacre sought to become the professor's next wife, it was no business of mine.
As I approached the door I'd been directed to, I felt like one mystery at least had just been solved, for a workshop would explain the overalls Roberta frequently wore as well as the soot liberally sprinkled all over them. Upon opening the door I was met by a wall of heat, such that I took an involuntary step back. If the very gates of hell had opened before me, I couldn't have been more surprised, and my first impression was reinforced by the steep, narrow staircase leading down beyond the door. This was illuminated from below by a deep reddish glow, which flickered and gleamed off the brick walls in a most disturbing fashion. There was also a roaring sound, such as a furnace might make, and the clatter and whirr of machinery.
After closing the door behind me, I started down the steps, and fortunately the heat grew a little less intense as I descended. The noise, on the other hand, increased. I once visited a textile mill, with its steam engines and giant rattling looms, and this sound was eerily similar. It was also the last thing one expected to hear inside a cellar.
I reached a turn in the stairs, and as I rounded the corner the noise grew louder still. I could now see a large fireplace set into the far wall, with grated vents providing fresh air from outside in order to feed the flames. And fed they were, for the flames danced, white-hot, upon a boiler almost large enough to drive a locomotive. A heavy pipe led from the boiler to a smaller receptacle, and from there steam pipes branched out, leading along both walls.
At the bottom of the steps