Encyclopaedia Britannica
I have the ninth edition of the Encyclopaedia Britannica (1875). And I also have the eleventh edition (1911, with 1922 supplement), which I prefer for its greater coverage, its thin paper and its leather binding. I don’t begrudge the four-and-a-half metres of shelving they occupy. It’s handy to be able to look up Primitive Methodist, or Poughkeepsie, or Piranesi in these time capsules.

You can get the same information — though not the pleasure of paper and binding — from a website. The unnamed authors of this site have scanned and OCRed the huge 1911 text. The presentation is rough, the navigation is basic, but the words are there. I hope that one day all this text can find its way into a hypertext database, like the modern Britannica.