Disclaimer: I've abused several fandoms in writing this fic, among them Harry Potter, The Wizard of Oz, and the general idea of steampunk. I own none of these, which is a shame.

Author Note: I'm taking it for granted that you know the canon progression of events in the Harry Potter universe. This story would take place relatively soon after the defeat of Tom Riddle. It breaks no canon events, and impacts no canon relationships. Well, aside from the ones I specifically mention in the story.

-o-

Negotiating with the Goblins was always tricky, and conventional wisdom had it that if you came back with all your original fingers, you were ahead of the game. But starting a negotiation by acknowledging that you owed them, and asking them to set their price? Wildly unusual!

Not that the warrior-bankers weren't happy to adjust; fleecing Wizardkind in the same old ways, time after time, had to become a trifle uninteresting. Which meant that Harry's offer to make amends for his trespass was attended by the best negotiators, and was scrutinized by an amazing number of onlookers … who apparently had to pay a premium for the right. Goblins weren't above fleecing each other, it seemed.

In the arena (what looked like a fighting pit outfitted with a negotiating table and chairs), Harry put down his box carefully, withdrawing a complicated piece of wood. "Ok, this is a slide rule."

The goblin on the other side of the table waved his hand. "We already have those. Better," he added eyeing the wooden rule.

"Ah, good," replied Harry. "Then you might find that this would be more helpful for specialized bank positions." He pulled a couple of smaller boxes out of the big one. "This is what non-magicals call a chain adder. It is only capable of addition." The flat box of gears waved in his hand.

"Then of what use is this to us, wizard?" That goblin was definitely hostile.

"Because it doesn't have to be keyed to base ten," Harry replied blandly. "I brought two different types, so you can see how different arrangements can work. This one," He waved the second model in his hand, "is set up to add the old pounds sterling currency. If you take this apart and understand how it works, you can make specialized machines for adding knuts, sickles, and galleons."

Harry pulled out the stylus and turned the gears to show how it could add farthings to pence to shillings to crowns to pounds. The goblins seemed to be unimpressed.

The hostile goblin sneered at him. "We have no need for your crutches, wizard. Every goblin can do all those things by touch."

"Well, yes," Harry easily admitted. "But the point is … wizards can't. Would you like to insure that wizards can keep their own books and so they aren't arguing over withdrawals and charges? Would you like to sell these machines to humans as an additional profit line? Or even better – would you be open to leasing them?"

The goblin scowled. Well, he scowled harder. "What is this lease?"

"You retain ownership of the item, and the wizard pays you a specific amount of money each month for use of the item. The item is returned back into your custody after the term of the lease expires, typically three or five years."

The goblins glanced at each other. "This is similar to the terms of sale for goblin metalwork."

Harry smiled – lips closed. "Yes, but with the terms explicitly stated, there will be less friction when the items come back into your control."

"Why do you offer this?"

Harry shrugged. "I have wronged the goblin nation, and I owe recompense."

"These are the work of your own people. Why do you offer them to us?"

"Because 'my own people' are idiots. They could be using these machines right now, but because they scorn the ingenuity of Muggles, they don't. This opens up an opportunity for you – and since goblins are masters of metalwork, I believe that you will find many ways to improve and extend these devices."

The goblins conferred among themselves. One announced to Harry, "This is a gift, but you have wronged us and attacked us a great deal. Your debt to us has decreased, but you still have debt to us." There was an approving murmur in the surrounding stands.

"Yes, which is why I'm offering this as well." Harry pulled out what looked like an ornate, fat pepper grinder. "This is a Curta mechanical calculator – it is the most complex and most capable mechanical calculator made by humans. These are no longer made, as electronic calculators are faster and easier to use, but this has the advantage of working in a magical environment. I believe that if you know how this is made, you will be able to make larger and more comprehensive machines. A human named Charles Babbage made plans for a completely mechanical computer, but was unable to make it work; with this you could take his plans, rework them, and own the next flurry of changes in the magical world."

The group before Harry were paralyzed. The lead goblin's eyes were slitted, and still. Harry sat back waiting for a reaction from the squat being across from him.

Finally, a goblin spoke – one of the lower ranked ones at the side, not the leader in the center. "How would a computer give us more gold?"

Harry cocked his head to the side. "Humans are finding that collecting large amounts of information leads to being able to spot patterns as they are forming, and they are able to take advantage of them. If you can make an accurate mathematical model of how the earth's layers move, you should be able to find hidden seams of gold."

A large wave of incomprehensible sounds came from the surrounding onlookers. As it receded, he went on.

"Or, if you have all the information about what money is being spent by wizards and witches, you can invest in the goods that are in demand, and keep from investing in goods that are not wanted. Or you could calculate the optimal fees to develop your new goods into a self-sustaining profit farm." Harry shrugged. "But your self-definition might not allow you to use agricultural metaphors."

The audience began arguing among themselves at Harry's suggestions.

"Many humans are using computers to find patterns in investments that allow them to purchase stocks before they are in demand, so they can resell them at a higher price. To generalize this idea, if you know enough about what goods are being bought and sold, you can purchase what will be in demand later and increase the prices to people that will need what you have."

The goblin response sounded quite favorable.

"And if you have a complete enough picture of the economic activity in a country, you should be able to detect any buildup of military forces or capabilities."

The sound was cut off as if with a knife. After a long pause, a small voice asked, "How?"

"I'm not sure," Harry admitted. "I have been told by someone I trust that it is possible. Maybe that only works in the Muggle world, maybe?" Harry carefully put the Curta back in its individual box. He only had the one, and it had to be in good shape to be a trade good. All the other examples followed it back into the box of trade goods Harry had brought.

"Well," Harry said, "this was just my first idea on providing something you might value in recompense for my trespass. I'll just take this away and come up with other ideas you might like."

The goblins exchanged glances as they waited for another goblin to make the first move. Finally, that same small voice called, "You are offering all of these services in payment of your debt?"

"Not at all," Harry said easily. "I am offering these devices, with some suggestions on how you might use them. I can hardly offer you your own metalworking skills, nor can I offer your own work in payment for my debt. I offered these devices, the cream of human ingenuity, as an opportunity, but … you made no offers, so I'm going to go back to my home and think deeply about how much I owe you and what I can do to make things right."

It's an old negotiating ploy, but that's because it consistently works. Walk away from the table with something they want, show that you can live with no deal, and they'll clamor to provide one. Harry sold the contents of his box, and exited the goblin nation with all his limbs (and fingers) intact. And his vaults, too – that was a biggie for him.

It was only 8 months later that Gringott's offered 'summation assistants' for lease to their commercial accounts. Wizards were able to easily – well, more easily, which was not the same thing – total their receipts, keep their books, and do the general accounting tasks that keep a business afloat. Businesses lasted longer, and made more money. More gold circulated through the hidden economy of the British Isles. Business wizards were frequently seen with a small leather pouch at their belts, to hold their 'SA', and their meetings shunned those without the mechanical calculators.

And yet, there weren't any Wizards that were significantly richer. The little flat, hand held gearboxes had sped up sales and payments, allowing stores to be open longer: the math devoted to tallying transactions had been reduced to an effortless five minutes at the end of the day.

Nobody noticed, and nobody complained, but if they had, they probably wouldn't have blamed anybody. It was just the way of the world; the pace of life sped up, and things went on the way they always had.

They should have blamed Harry Potter for introducing the concept of 'cultivation' to the goblin's relationship with the Wizarding economy.

-o-

And deep underground, is a carefully reinforced cavern, where the air is a constant temperature and the humidity never varies and the other races will never venture …

… a new thing is beginning. Charles Babbage would have lost his mind, Maurits Cornelis Escher would have hmm-ed thoughtfully, Ida Lovelace would have squealed in glee. And Lyman Frank Baum would have nodded approvingly.

Tik-Tok the Mechanical Goblin was taking shape.