I haven't found a picture of ALC, and few showing Hoe presses other than the large web fed presses used for books and newspapers.
Here's another catalog or ad for Hoe,
http://www.librarycompany.org/pos/ex...images/2.8.jpg
The description says up to about 1000 sheets/hour.
And here's a nice pic of another big litho company from 1905 using a different companys preses, but very similar.
http://www.newworldencyclopedia.org/...d_Mfg._Co..png
Most lithographic shops have a variety of press sizes. The one I was at had a little one, maybe 10"? Two 35 inch and a 24 inch. They later added a 35 inch two color press.
Most presses can be adjusted to run smaller paper sizes, but it's not usual to do that. For any particular job there's an optimal press size, and that's what's used.
ALC was huge, and the floor layout shows just one floor. They probably had another 2-3 floors with different size presses.
A sheet 17x6 would be an odd arrangement. The image area would be just under 24.43 x 15.75. On the number 1 press it would be too large and on the number 2 size it would fit ok in 22x30, but with huge margins that would probably lead to too much waste. 17x8 would work, but with wide side margins, not bad but still not great. (24.43x21)
18x8 gives 25.86x 21. half inch margins top and bottom, and just over 2 inches on each side.(plus the built in margins of paper size vs image size shown in the ad)
Not bad......And with complex layouts using doubleprints and/or superprints it easily accomodates both the groups that fit well with 6 or 12 subjects as well as those with 17.
Hmmmm......that may make the most sense so far.
Although they could have easily gone to 20x8, the 18x8 layout could conceivably also have been done as 3 small sheets of 6x8, allowing a bit more flexibility with the back printing. That might also explain the cutting guidelines on the reverse where they don't make much sense.
Steve B