1960s Typing and Typewriter Technology
For mathematics grad students in the mid-1960s, not to mention professors and any professional working in the field… choices for how to produce a technical paper were limited.
The lucky few who managed to get their papers accepted by a journal, hit the hot metal type jackpot. According to Dennis’ school colleague Mike Fischer, “Papers in refereed journals would be professionally typeset by the publisher. Galley proofs would be returned to the author for correction of typos and then printed using the printing techniques that were standard at the time. Professional typesetters had many special symbols available, and they had a good eye for adjusting the spacing of characters to get a pleasing result.”
This technology was “mechanical typesetting” or “hot metal typesetting”, which was developed in the late 19th century. This was just before the advent of photo-typesetting.
Dennis and Albert Meyer wrote a paper, “The complexity of loop programs*”, which was published in the Proceedings A.C.M National Meeting, 1967. This must have gone through the process described above. Open the link to the paper and browse through its pages, they are beautifully typeset. The letter spacing is proportional (less space for an “i” than for an “m”, sub and superscript characters have a smaller font and make only a partial vertical adjustment, not full line height. This was luxury!
But for most students, the only option was to type their papers themselves on a typewriter. Many students would type early drafts and revisions themselves then hire a professional typist to produce the final version. Technical typing was a thriving vocation in the 1960’s, many theses were typed by department secretaries, many independent contractors available for hire as well.
In 1967 there were basically two types of typewriter to choose from:
- The IBM Selectric, introduced in 1961, which used a spinning golf-ball typing element
- The Traditional typebar typewriter… IBM Model D, introduced in 1967, as well as the Model C, Olivetti, Royal, other “typebar in basket” style machines
The Selectric was a completely new concept in typewriting… the platen and type ball element moved across the page while the paper remained stationary, instead of the paper moving with the platen across the keyboard while the typebars always struck the same spot in the center. This design provided easy access to type-ball element so it could easily be swapped out for another golf ball. IBM promoted this feature heavily and produced many different type fonts and special characters.
IBM Model D
The IBM Model D (and Model C) had a different system for typing special characters. The four outside typebar sticks could be removed and replaced by special character sticks that the typist would then strike. You stored your stash of special typebars in a wooden IBM box, the company stocked a wide range of characters and symbols. It was a tedious process to swap typebars in and out, but some typists could swap out a stick faster than a golf ball.
“I believe the secretaries at Harvard in the mid-1960’s were using either the IBM Model C Hektowriter or the IBM Model D, introduced in 1967. They looked very similar, and there was probably a transition period when both were in use. They were the last of the typebar typewriters and would have worked with the box of manual special characters that I described on the phone. (I still can’t find any mention of them on the internet, but I’m certain that my professional typist used them when typing my thesis, which was also full of them.)”Dennis’ Bell Labs colleague, Stu Feldman, described the typewriting situation in an email explanation:
“On an IBM Model D (standard or executive), you could get several removable type bars at left and right of the basket (I think that was a standard special order, not sure if it was the default) and you could order special keys out of the catalogue that would fit into exactly one position in the type bar basket.
“An after-market option was the Typit that would work on a variety of typewriters. You installed a special bracket where the keys struck. When it was time for a special character you pushed the appropriate stick (plastic handle with a character in front and a rod in back), then typed any key (preferably one in the center of the basket to get a clean strike ) and it would smash into that rod and print the character rather than the one on the bar. This depended on each bar’s having a blank spot between upper and lower case. If you misaligned the bracket or didn’t put the Typit in correctly, you smashed the letters on your typewriter…)”We’re pretty sure that non-IBM traditional typewriters, such as Olivetti and Royal, did not have removable typebars but they did accept Typits. These were certainly in use typing mathematical papers in the 1960s, just not cutting edge.
The Model D (and others of its style) had an one important advantage over the Selectric. When adjusting the line height for a subscript or superscript, the typist could twist the platen to advance the paper by “one click”, or one half a line height which works out to 1/12 inch.
Responding to our description in the Anatomy of a Thesis section that the dmr thesis was built on a 1/12” by 1/12” grid, Dennis’ colleague, Mike Fischer, said this:
“The fact that it was typed on a 1/12″ x 1/12″ grid is no surprise to me. 12 characters/inch was the standard “elite” typewriter. 6 lines/inch was also standard, but the IBM typewriters had a platen that would allow half-spacing, i.e., 12 half-spaces per inch. So there was no need to do manual continuous positioning in order to type a page where all letters ended up on the grid. Rather, in order to type a superscript “2”, one would roll the paper down one click, type the”2″, and roll it back up one click to continue. This of course was rather clumsy, and other typing order might be possible. For example, if one is copying an existing line with superscripts, one might leave a 1/2 line for the superscripts, then type the line with spaces where the superscripts are needed, then move the paper down one click, and go back and fill in the missing superscripts. I don’t recall, but this is the kind of thing that I would have thought of at the time and might well have done myself since it greatly reduces the amount of platen movement.“
The Selectric did not have a positive “click” adjustment to achieve a ½ Line Height shift. If you wanted to type a subscript on a Selectric, you had to adjust the paper height manually.
According to Jerry Saltzer, inventor of Runoff (famed early text editor), sub-and-superscript adjustments on the Selectric had to be made by hand…
“With the Selectric typewriter, not only is the platen pin-feed, it seems to be driven by a gear and ratchet to maintain precise vertical alignment and interline spacing. But there is also a lever, called the Line Finder on page 15 (PDF page 17), that can release the ratchet so that the operator can temporarily position the line up or down by hand. The Line Finder lever then can re-engage the ratchet to realign the platen on the original line.”
The Cardholder (Selectric Operating Instructions page 16) provides both vertical and horizontal alignment lines.
It looks like the cardholder’s alignment lines, used in conjunction with the Line Finder, would allow a perfectionist with a good eye to do a good job of aligning sub and superscripts.
We have more research to do on how typists of the day used the Line Finder, and in practice how the Line Finder compared to the “half-line platen click” of the Model D. We’re looking to talk with more people who typed their theses in the 1960s and can remember how they did it.
Reality is that none of these typewriters was designed to handle mathematical papers well. Typing a math paper during this period was a very difficult process, very hard to achieve good results.
Dennis’ colleague, Mike Fischer, describes his own experience this way:
“With my own thesis, I began by typing a rough draft myself that I then edited using scissors and tape and pencil and white-out.Once a page became too patched up, I made a Xerox copy to create a clean new version that I could then edit and chop further as needed. Once my draft was finalized, I paid $500 to a professional typist ($4,300 today) to retype it into a final dissertation that I could bind and submit to Widener Library. I specifically recall that my typist used typebar special characters, which would have meant that she used an IBM Model C or D typebar typewriter.“
Brian Kernighan described the general state of typing affairs in the mid-1960s in “UNIX – a History and a Memoir”, pg 99. –
…It may be hard for readers today to appreciate just how labor-intensive it was to prepare documents before the creation of word processing programs, when there were only mechanical typewriters – better than clay tablets or quill pens, to be sure, but any change of more than a few words in a document would require a complete retype. Thus most documents went through only one or two revisions, with handwritten changes on a manuscript that had to be laboriously retyped to make a clean copy.”
In 2010, mathoverflow.net launched a discussion asking people to describe what it was like to type a math thesis before LaTex became available in the 1980s. Here is a link to the discussion board and a sampling of the descriptions from that thread:
“I typed my thesis in late Winter 1963, on an IBM Executive in the Bowdoin College Math Dept office after hours. This was before the Bouncing Ball (Selectric), but it had two or three removable type-bars at the side, and we had a couple of dozen special bars, each with its own character. If you wanted to type “αβαβ”, you’d have to remove the alpha-stick and attach the beta-stick. I think that there were relatively few characters I had to put in by hand: pp maybe, and certainly the inclusion symbols. It took me 45 minutes or so per page, and according to the rules at Harvard, there could be no corrections on any page (not even white-out).”
“I paid a secretary through the nose to type my thesis in 1964, doing much of it myself, and using carbon paper to get a copy. Lots of handwritten graphs of spectral sequences. The memory of that horrid process may be one reason I never published my thesis. It is roughly 150 pages of dense calculations.”
“My father was a mathematician, and, before the IBM Selectric typewriter, I can tell you that he bought an expensive manual German typewriter along with boxes of these plastic sticks, each with a metal head containing a math symbol. Very slow and very painful.”
“Later, department secretaries (there used to be more of them) would have IBM Selectric typewriters, which would use a metal coated plastic ball, and you would switch the ball to get different symbols. This normally worked pretty well, except sometimes the teeth on the bottom of the ball (which was serrated for some reason) would break. This would mess up the typing action, so it would no longer type the symbol or character properly.”
“I paid the technical typist in our department to type my PhD thesis on her IBM Selectric typewriter. After it was complete, I noticed that she had omitted an entire paragraph of one of the proofs in an early chapter. To correct this would have required her to retype a large chunk of the thesis, so I let it pass. During my defense, the external examiner remarked that this particular proof was a little terse…”
You get the idea… it was hard back then. The next step for us is to examine pages from the elite math dissertation theses of the day, then present them so that we can all see how the typists handled complicated equations and what were the actual standards from the time that we can measure against. Below are the images of our first round of evaluations, we haven’t had time yet to evaluate them ourselves.