> The easy moral of the story is that Twain was gullible and Paige a huxster.

It absolutely isn't. Paige was actually the engineer/tinkerer earnestly developing this machine, which really worked. One of his main problems is that he always thought he needed to improve it more before it was ready. He didn't understand "release early and often": that time-to-market matters.

> Twain felt that he had an insider’s perspective and could intuit how others in publishing would respond to the machine. But he was a printer’s devil no longer: he was a famous, millionaire author.

No longer, perhaps, but Twain had been in the printing industry, so he knew a thing or two. From age 13, Twain worked as a typesetter and compositor for newspapers. So even if he overestimated his knowledge of that, it was not simply the conceit of someone cushioned. What he remembered from his past experiences with freely moving type set by hand would have still been relevant at the time he embarked on this thing with Paige. Linotype was not yet in the market.

Even as the Linotype appeared, it was not obvious that it is superior. It is a gross simplification to say that Paige's machine was imitating manual typesetting whereas the Linotype wasn't. Both machines work by moving letter blocks into rows, and the letters have to be sorted.

Evidently, what the Linotype did better was:

- Linotype characters are negatives, made of brass. Brass is hard and durable. These negatives are cast to positives with molten lead. The lead is melted for reuse after a run of the typesetting. Paige used cast lead pieces, which were more or less permanent. The same letter "A" would be used over and over again in different typesetting jobs. Lead is heavy to move around in the machine as well as soft. Brass allows nicks or slots to be cut in it for easy sorting into bins, but if you do the same with lead, it won't be durable; these features will wear out and cause missorting and jams.

- Paige's system used a complex system for justifying words and filling spaces at the ends of paragraphs and whatnot; it had to calculate and insert spacers. Linotype had clever tricks: special wedge-based expander bars were inserted between words, and then pressure against the bars expanded the sliding wedges to justify an entire line at a time. So in that regard, that's where Linotype deviated from trying to imitate manual typesetting.

- A key difference is that Linotype makes one line at a time, out of brass moulds, with spacers between. This is then cast with molten lead: just one line, called a slug. After a line is cast, the brass moulds can be released and sorted back into bins. The lead slugs are assembled into a page. Paige's system, maybe because of his surname, tried to work more traditionally, typesetting a whole page. That creates a problem because of the limitations of the workspace. If you are doing lines separately, you can have machinery/tooling/jigging above and below the line; there is no consideration for interference with previous or subsequent line of text. This freedom is what enabled the mechanisms for spacing to be developed.

But the thing to note is, that the Linotype changed typesetting work into something more heavily industrial, involving continuous hot metal casting.

Paige and Twain might have been betting on such a change being rejected by the industry, in favor of their solution which was doing the same sort of typesetting.

The “mechanical miracle” that ruined Mark Twain’s life