How would you describe a PC to someone 150 years ago?

How would you describe a PC to someone 150 years ago?
This is really more of an intellectual challenge to all you answerers out there, since I've clearly got no time machine to test your answers with. :)

The challlenge: convey the power, flexibility, and mobility of the modern computer to someone say... pre-telephone era. (Yes, this isn't quite 150 years, but still).

The year is 1856, The Republican party has just been formed in Pittsburgh. James Buchanan has just been elected president. Edison will not invent the light bulb for 23 more years, and there is no reason for anyone to have electrical service, even it one has been offered.

Babbage's difference engine has been constructed after his death, and is the closest device on earth to what we know as a computer.

Anyone trying to explain a PC in that environment would be considerd a lunatic, particularly because the technology could not be easily demonstrated or replicated.

you can't. that would be too hard. Besides they wouldn't believe it.

To a person from 1856, I would use one word: magic.

Everything you want to know at your fingertips.

Imagine 50'000 secretaries all helping you at once. Now a machine does it.

its like a black&white TV, but it also have key-board, like a typewriter, and it also have mouse, mouse is like a potato, but it also have a ball inside of it,
in that black&white TV you can view your pix and movies, and aslo you can type in it.