> I suppose it's possible that the "New and Improved Duplex Pumper"
> gave Lauter some 'bragging rights' of a sort.  The fact that Lauter
> returned to making the regular exhauster assembly just a few short
> years later probably points to the fact that the gimmick didn't work,
> or was, at best, only mildly successful.  Dare I say that other
> companies quickly challenged the idea as 'hype', which in turn only
> served to tarnish the fine reputation that Lauter enjoyed.

From a(n) historical standpoint, there are several possibilities.
One might be the advertising or novelty strategy cited by Mr. Tuttle.

And there is always the possibility that someone powerful in the
company had the idea for such a pump and was able to prevail upon the
designers to include it in the product.  Might have been a project of
the owner's dissolute son (there's always a dissolute son in industrial
sagas.)

But my suspicion here is that it's all due to a common cause of weird
design: patent considerations.  Probably a competitor had managed to
patent -- or had submitted a patent, or was suing to defend a patent --
on the standard exhauster pump.  But such a patent could have been
denied after submission to the Patent Office, or declared invalid in
court, or purchased by Lauter, or circumvented by a clever designer,
after which the production of the 'duplex' could be discontinued.

Some very strange designs have resulted from patent wars.  James Watt's
early steam engines didn't use a conventional crankshaft: they had
a planetary gear arrangement, because someone else held the patent on
the crankshaft.  (I know that sounds strange, but that's what I read.)
And early radios used some overwhelmingly strange circuitry to get
around patents of straightforward designs.

Thos. A. Edison was a master at this sort of thing.  Edison had
patented the best telephone transmitter: the carbon microphone, still
in use.  Alexander Graham Bell had patented the electromagnetic
receiver: again, it's still in use.

During the extensive court battles that followed, Edison had to come up
with a complete telephone system for some legal reason.  So he designed
and patented a triumphantly weird telephone receiver which required
a pan of water and a hand crank to operate.  I'm not making this up;
apparently the silly thing actually worked.  But its only purpose was
to make a judge or a jury happy.

Mark Kinsler