Silencing charm! Very very long letter to his father! And he settles in and starts reading.

Cam asks Bar for a meal recommendation, which he buys with counterfeit and eats while he works.

The future has lots of stuff and he has absolutely no scientific education. This is very interesting reading.

"Do go ahead and ask if something is too void of context."

"I've just been presenting it all to my father as a puzzle, I bet there is enough context and it's just that I'm not good enough with it and he'll be able to come up with an explanation."

"I will be very surprised if Introduction to Concepts of Programming published in 2038 has enough context for people in 1802 who are not personally Charles Babbage. Maybe not even him, when was he -" Looks it up. "He's currently thirteen in your world, so likely not even him."

"I will tell him that you said that and then he will try twice as hard. Might still be beyond him, I don't know, but there's also enough here that I'm not in a hurry to get to Introduction to Concepts of Programming either."

"Well, there's 'information-theoretically possible to extract value from' and 'enough'."

"Okay, okay, what is programming and why would Charles Babbage be able to do it."

"He invented the concept. Maybe unless you count Jacquard, who may have done his bit already, but Babbage is more directly relevant to computers. Programming is how you get computers to do things that are not 'sit there' and 'inefficiently heat the room'."

"And computers are your little stick thing -"

"Computers start as monstrosities that take up entire rooms and can barely add two-digit numbers. Eventually they are my stick thing that obeys my thoughts and is cryptographically secure against demons and can hold more writing than the entire human race has as of 1802 produced."

"- wow -"

"I'm fond of my stick thing."

"I bet. Any guesses as to why they don't work in Hogwarts -"

"Are there other things that likewise won't?"

"There's the thing Minor's constantly toying with - with the voltaic piles - he got electric eels in to check if they worked, they work fine, so it's something else going wrong with voltaic piles -"

"Brains work on electricity too, so it can't be electricity generically, eels or no eels. I suppose wizard brains might run on magic, so the eels rule out 'wizards are the only organisms with brains to set foot on the grounds'... metaphorical feet..."

"There're wards to stop Muggles from coming to Hogwarts but I don't think they'd die if they did. I could fetch Minor, ask if he's gotten anywhere on the theories."

"If you have sparrows on the grounds - nonmagical ones, I mean - then electricity generically is not the thing. And lightning, do you have that."

"We have both lightning and sparrows."

"So orderly inorganic electricity, or something. Does clockwork behave?"

"I have never heard complaints about it misbehaving and there are five Ravenclaws in the family."

"I don't know what a Ravenclaw is, except in the uninformative orinthological sense."

"Students at Hogwarts are, at the age of eleven, sorted into one of the four Houses by a magic hat that reads your personality and places you accordingly. The houses are Slytherin, the house of ambition and cunning, Ravenclaw, the house for the love of knowledge for its own sake, Hufflepuff, the house for the classic virtues - perseverance, hard work, justness - and Gryffindor, for bravery and passion."