Cómo encontrar imágenes en el dominio público [en inglés]

Recently I got fascinated with images that can be found in old books. In this post I’d like to share a couple of tips on how to find such images. It’s easy and fast, because there is a possibility to search digital files of books that entered public domain.
Images from books published a hundred years ago are the same source of inspiration as pictures you can find on Flickr. These illustrations, very often made in a process of wood engraving, are sometimes funny, sometimes surprising, sometimes brilliantly weird – but always very well crafted.
Finding images in ebooks is not as straightforward as on Flickr or Imgur, but as I said – it’s easy. You don’t need to download the ebook, open it in an e-reading app and go page through page to find an image.
You’ve got to know only two things:

  1. Which sites offer public domain ebooks in html format
  2. How to search images using Google

Public domain ebooks are as a rule free to use, so there are no limitations regarding formats (no DRM is required). In most cases these books are offered in html format, in addition to pdf, epub, or mobi.
Having the book file in html gives two benefits. One is that the book can be read online, in a browser, so you don’t have to download it if you want to read it. The other benefit is that the content of a book can be accessed by Google web crawlers – and that means it can be searched by anyone.
There are a couple of great sites where public domain ebooks are available in html format. Most important ones are:

Generally, it’s these three sites where any public domain content is revealed to web users for a first time. Other sites are in most cases republishing the books. For more detailed information about the sites, please read my overview ofplaces to read books online.
Now, here comes the second part – finding the images. It’s quicker than you think, as you can do it from within Google web search.

How to find images in public domain books

1. In a Google web search type the command that limits search to one site only. For Project Gutenberg this is:

site:gutenberg.org

You can follow it with a keyword or key phrase you are looking for:

site:gutenberg.org library

2. Now the only thing to do is to click on an image search tab:
Finding images in public domain ebooks
Below there is a screenshot with wonderful images from Project Gutenberg returned for a “library” query (click on the image to enlarge):
Project Gutenberg - images from public domain ebooks
I’ve also tested the other two sites, but there is much more contemporary content there, so illustrations from vintage books don’t come in bulk.
In fact, Project Gutenberg is perfect for old image search. There are over 40,000 books in PG’s catalog, not all books have covers, and there is not too much image stuff that is not a part of books’ content. As a result, most of the pictures from Project Gutenberg are the ones found in html files of 40,000+ public domain books.
You know what’s most fascinating about these images? I never imagined I would be able to have a chance to see such images in a book published 100 years ago in London or New York, and probably being in catalogs of few libraries in the world.
Digital format lets old books live again.
 
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