the jsomers.net blog.

Yesterday a paper I was reading made reference to a "Galtonian composite photograph." From the context I had a vague idea of what the phrase referred to, but I wanted to learn more. So I:

1. Googled "Galton" and clicked on the first result, the Wikipedia page for Sir Francis Galton.
2. Searched the text there for "composite," which turned up the following:

   Galton also devised a technique called composite photography, described in detail in Inquiries in human faculty and its development...

3. Googled once again for "Inquiries in human faculty and its development" (no quotes), which turned up a complete Google Books entry.
4. Searched inside that text for "composite," and found, finally, "Appendix A.—Composite Portraiture," which contained everything I might want to know on the subject.

The whole process took about two minutes.

I couldn't help but wonder, though, what my search would have looked like forty years ago, long before the Internet and the proliferation of personal computers. How would I have traced a casual allusion to its source?

Step 1: Go to the library

Short of phoning a friend, there would have been no way to look something up without going to some sort of library. If I lived in the sticks, my best hope would have been a wealthy resident's set of encyclopedias or some sort of bookmobile—essentially a cart that hauled boxes of books around to small towns. For any remotely obscure topic, I would have been out of luck.

Step 2: Card catalogs and the metasearch

Once I got to my local library, probably funded by Carnegie, my first task would have been to figure out where to start looking. It's a process that has been mostly obviated by search engines, whose crawling and indexing and relevance rankings allow one to scour the whole world at once, without much regard to where the info comes from.

Back in the day, though, I would have had to start a sort of metasearch to find the right books, periodicals, journals, or microfilms in which to begin my actual search.

Luckily, by the 1960s these materials were indexed exhaustively in large card catalogs, which mapped author names, titles, subject headings, or keywords to the precise coordinates of actual items.

Not so luckily, I would have had to know some author name, title, subject heading, or keyword to look for. In the case of my query above, "Galtonian composite image," I would have had several plausible angles of attack: the name "Galton, Sir Francis," which if I didn't know, I could discover in an encyclopedia; the key words "composite image"; or the subject heading "photography."

But what if I had no context for my query? For example, what if I ran into a sentence like, "He resembled Little Chandler, if not in size then in stature"? Clearly this is a reference to some moderately famous person or character, but without more to go on, how could I figure out what to look for in the card catalog?

It depended. If I suspected that this was a real person, I could have searched the Encyclopedia Brittanica, something like the Dictionary of National Biography (for dead people), or a Who's Who (for living people). Once I found my man, I could pick up a biography or two.

Finding a fictional character would have been more difficult, but still possible. There was actually something called the "Cyclopedia of Fictional Characters," or I could have consulted the once-apparently-indispensable "Benet's Reader's Encyclopedia," which in addition to characters also catalogs author names, novels, stories, literary terms, etc. If I had gotten a handle on where my character first appeared, it would then have been a matter of picking up that particular book. Problem solved.

Unfortunately, it turns out that "Little Chandler" doesn't appear in any of these. Which means I would have had to either ask a librarian—who might have some tricks up his sleeve (Dewey, of the Decimal System, once said, "...the librarian must be the index of indexes")—or a very well-read friend, or maybe a professor of literature.

Step 3: The deep crazy world of indexes

Supposing I did have some success with the card catalog—as I would if I were searching for "Galtonian composite photography" instead of "Little Chandler"—I would now be sitting at a table with a large stack of reference works, regular books, a newspaper microfilm, and maybe a few journal indexes, which are like regular indexes, but span the full output of hundreds or thousands of journal issues.

Indexes, by the way, are curious things. They don't work the same way as Google's "index," which is, in technical parlance, really a concordance, because it maps every word to either a snippet or the full text of the page on which it originally appears. Concordances, because they are such a pain to compile by hand, were really only created for stuff like the Bible or the works of Shakespeare. (Example.)

Real indexes (don't say "indices") only contain a small, carefully chosen subset of all possible terms. They're put together by professional indexers who work for publishers on a contractual basis. (Some authors do write their own indexes, but this is apparently frowned upon by the American Society for Indexing and one of Kurt Vonnegut's characters).

Theirs is difficult work. Indexers must take care to use a controlled vocabulary, i.e., a set of canonical headings that "solve the problems of homographs, synonyms and polysemes by a bijection between concepts and authorized terms." The idea is to avoid multiple entries like "Cats, 50-62" and "Felines, 175-183", and to make sure not to confuse the two meanings of words like "pool" (think swimming and billiards).

They must compose a semantically sensible and reliable syndetic structure, which is the complex network of inter-index references ("See also...") that link related topics. It's important to avoid circularity (A -> B -> A) and to consistently connect semantically "close" entries (i.e., if "General Patton" points to "WWII", you probably also want "General MacArthur" to point there). To do so requires a fairly detailed understanding of the book and its subject matter: Which topics are related? Are these four ideas subunits of some general concept? Is X important enough to index?

Finally, good indexers have to put themselves in the reader's shoes. What sorts of things will someone new to the subject be looking for? If they want to know more about X, what word will pop into their head? Will they care to see the reference on p. 124, or is it too cursory to be included?

There are whole journals devoted to the subject. In fact, if you want to see a great index, presumably you couldn't do much better than the journal index for the journal Indexer. (Among other things, there is a section in each issue devoted to "praising" and "censuring" indexes found and submitted by readers. Down the rabbit hole...)

Step 4: Read, read, read

In any case, to return to my hypothetical 1960s search, I would now be (reverently) perusing the indexes of each item in my stack. I'd be looking for words like "Galton" and "composite," and I'd quickly skim the text of every reference until I found something promising. If yet more books were mentioned—or if I found some encouraging titles in a bibliography—I'd dig them up as well. My stack would slowly grow, and recede, and grow again, as I discarded dead ends and pursued new leads.

In contrast to how things work today, I wouldn't just be reading the stuff most directly relevant to my query. I'd be tempted by all sorts of tangents along the way: unusual or obscure topics, or hilariously terrible writing, or some new fantastic author I'd never yet encountered. In the search for truth I'd be taking the scenic route—longer, sure, but maybe more rewarding.