Between 1848 and 1873, self-styled “theatrical publisher” Thomas Hailes Lacy published 100 volumes of Lacy’s acting edition of plays, dramas, farces and extravagances, etc., etc., as performed at the various theatres, each containing fifteen titles. This proved to be a highly profitable venture, which Lacy passed on to his friend and former collaborator Samuel French shortly before his demise in 1974, and which continued to be published into the next century.
Individual volumes in this edition carry no publication date, though we may assume they appeared in the order suggested by their number. Individual titles within the volumes are (almost all) blessed with an alleged date of first performance, however. Consequently, the best we can do to assign a date of publication to (say) volume 98 is that it is later than that of volume 97, and also later than the first performance date of any play it contains. Assuming we can rely on these performance dates (we can’t), it seems natural to wonder whether each volume contained a mix of old favourites and recent novelties. If there’s a mixture (and there is), is the ratio of old to current constant or does it change over time? And do the contents of each volume remain stable over the whole period of publication of the edition?

Here’s an infographic (click to enlarge it) which may help resolve some of these questions. Each vertical line here corresponds with a volume, numbered left to right from 1 to 97. Each vertical line contains differently coloured chunks corresponding in length to the number of titles in that volume whose first performance date lies within a given decade: the decades are colour coded. For example, the line for the first volume shows 7 “blue” titles (first performed before 1845) and 8 “red” ones (first performed between 1845 and 1854).
Almost every volume has a “blue” chunk, but the other colours are localised to particular groups of volumes. The number of “blue” titles — those first performed before Lacy started publication — is between one and five throughout, though a few volumes have more than eight. We may think of these as old war-horses or as steady background noise, occasionally building to a crescendo (as in vols 23 or 95). However, the majority of titles in most volumes are dated to one or other of the periods 1845-54 (red), 1855-64 (yellow) or 1865-74 (green). Titles from the earliest (red) period do appear after volume 25, but rarely more than once or twice per volume. Similarly, titles from the middle (yellow) period dominate volumes 25 to 68, with much reduced numbers continuing into the last period, which is dominated by titles from 1865-74 (green). It is hard to avoid the conclusion that Lacy astutely leavened the mix for each volume , using mainly contemporary titles to complement the old favourites.
This visualisation also exposes some oddities in the data. About twenty volumes have plays for which no performance information is available: these show up as white chunks. Three volumes have titles performed after 1875, which should not happen: on inspection, their dates are indeed dubious. And there are doubtless other oddities which it hides. My data so far derives from inspection of only two different sets of the Editions, along with a random selection of the advertising pages listing available titles: it is possible therefore that the contents of earlier volumes change more frequently than appears to be the case ; however I have so far found only 12 cases in which one title is replaced by another in a (presumably) later edition.
(This is a revised and improved version of an earlier investigation.)
