I'm with Gabel, variations of electric driven portable mortisers have long been available in overseas markets. There was a market there, while there was none here, and those market forces still influence, what, is available from where today. Demand from our direction doesn't amount to much more than an irritation, which is why Ryobi (love my R-HCM's) and Hitachi (sold back my housing router when they bailed, – yup despite my deep disdain bodering on hatred for routers, the numerous daps demanded by common purlins meant the cost of labor won out over health concerns – The real threat of no parts decided it , despite how well designed – better than the Mak – powerful and shim-able it was) And I'm guessing, this is a big part of why the full line of Makita offerings is still not available here.
I am not convinced there was a falling demand and a failing market influencing new mortising technology as the 19th century came closer to its close.
As I stated in the other BM thread, many many variations continued to be patented through the last half of the century, the last I found was ' 99, and catalogs continued to offer them for sale into the 1920's. And yes, the first stick frames hereabouts date from the late 40's, but timber continued to be the material of choice in public buildings – town halls and churches - This, and a demand for barns and bridges - in a building boom (which did abate during two recessions) in an expanding America which happened to be blessed with a seemingly inexhaustible supply of an easily worked building material , continued to contribute to a sustained demand on into the 20th.
Fewer of the bells and whistles variants survive because fewer were sold, that aspect of human nature hasn't changed. Then as now, we buy just a smidge above our means (well, we can stretch our means a little more than those we follow) And the KISS principle might maybe have still been important to people as practical as carpenters tend to be, despite the propensity of people to accept every innovation as an improvement over yesterdays lot.
And I'm sure the many overly complicated variants might well have (told'ya about my machine so pristine) gone to scrap. While we might spend wonder over what in truth might be a poorly performing machine, no carpenter from the day was gonna wax romantic over something that didn't perform as advertised or needed, and then put it in the best'est and dry'est spot he knew to store stuff...
Here's a few more of the myriad of variations that were patented -
This is one of my favorite letters patent, not because it is recognizable to me, or in that it is a hollow chisel and a little ahead of its time, but because it speaks to adjustability, and the inventor is seemingly interested in ( could this be ) planes of reference, more than he is just slap it down on that imperfect surface and go. What were those planes of reference ? Judging by the wheres and whens I'm guessing this one never went into production and no physical example exists to try to cypher out the maybes. Another casualty of war ?http://www.google.com/patents?id=CAJkAAA...ges&cad=0_1
As example of the what we know as outside the norm, here's another patent from ' 60 -
Though, his actions ten years later suggest that first patent may have paid dividends, and though ten years time finds Mr Smith has now moved further west, his inventions certainly don't move towards the simpler -http://www.google.com/patents?id=BgpYAAA...ges&cad=0_1