I never gave a second thought to using bottle jacks in any position,
until I tried to use one on it's side, in other words, jack something
horizontally. The jack did not function. I grabbed another jack and
found the same problem. I researched this, and found that these jacks
are not meant to be used on their sides, and learned the reason, which
is all because the fluid must be on the bottom to operate.

Now that I fully understand how these jacks work and their limitations,
I'm still looking for something to move heavy objects on a horizontal
plane. These uses may be to move a small shed a foot back, because that
once small tree has grown large and is touching the overhang. Quite
recently I was putting plywood sheets in an attic and laid down 8 or 9
sheets, only to discover that they should have gone a few more inches
toward the rear of the house. They were not nailed, so they could still
be moved. The thought of putting a jack against the front rafters and
moving all the sheets at once came to mind, but I knew that was not
possible due to the limitations of these jacks. Therefore, what could
have been a simple task to jack these sheets over by 3 inches, meant
moving each sheet by hand one at a time.

Having dont lots of building of darn near everything over the years,
I've seen a need for some sort of jacks, as well as clamps and other
devices to move large or heavy objects on a horizontal plane. Yet,
there is nothing made to do this. Bottle jacks dont work on their side,
C-clamps, and Pony clamps all tighten INWARD. Of all the tools onm the
market, there seems to be nothing made to move heavy objects OUTWARD.

If you're erecting a wall, and the wall is a little off the floor on one
end, a C-clamp or other clamp will pull it inward. But to move it
outward, your only method is to use a big hammer (which in some cases is
not possible, such as the plywood attic floor).

Yes, there is the "come along". That tool will work in some places with
a large open area behind it, but it wont work to move a plywood attic
floor or even a shed if there is nothing to attach it to.

Am I the only person on Earth who seems to need a jack or other tool to
move heavy objects on a horizontal plane, or have the tool designers
just neglected to design such tools?

What is needed, is a small and short bottle jack that works on it's
side, as well as a C-clamp that clamps OUTWARD. And probably more tools
that work simularly.....