One of the dull but necessary tasks I do as a dance historian, right up/down there with reading terrible Victorian novels for their dance references, is comparing different editions of the same book to see what changed over time. Most of these comparisons aren't as exciting as, say, Dance Mad, which underwent enormous changes in less than a year in its second edition. But they're still useful for very fine-grained dance tracking, particularly in 1914 when things were changing very rapidly and the tango, maxixe, foxtrot, and half and half either originated or were enjoying bursts of popularity. And that's before even getting to the fad dances like the Lulu Fado, the Ta Tao, and the Furlana.

Comparing two editions of Caroline Walker's The Modern Dances is pretty tame in comparison, since the changes are mostly just in pagination and arrangement of photos, but it's still a useful window into how rapidly things were changing in 1914.

For reference, here are the known editions with their very helpful specific dates:

First - January 27, 1914
Second - February 12,1914
Third - March 20, 1914

That's impressively fast! The second and third editions were only five weeks apart, but apparently the major change, the addition of the Argentine Tango, was important enough to warrant not just an added section but also renumbering of the illustrations and having a few rephotographed completely to alter the recommended positions.

I own a copy of the second edition, and the third edition is available at the Library of Congress website. I have never seen a copy of the first edition, so I will be comparing only the second and third...[with a fine-toothed comb, behind the cut]