I stumbled into my study late one night without my glasses on, and reached for what I thought was my cell phone. It was not. It was this:
Published in 1896, it was the right size to fit in a man's vest pocket, and it was full of useful information for the day, such as the origin and names of fabrics (page 30); the number of trees on an acre (page 71); the distance traveled by a horse in plowing an acre of land (page 128); and the first lightning rods (page 236). It's not hard to imagine an know-it-all reaching for this volume in a bar in 1900 to smugly say, "I'll find the answer for you!"
But it is exactly the same size, and the same heft in the hand, as my 21st century version, the iPhone SE.