Father Borghesi specified that the entire mechanism was equal in weight
to a seventh part of a _Centenarii Germanici_, a Germanic hundredweight.
This is probably the Austrian centner which is equivalent to 123.4615
pounds. Therefore, the clock mechanism weighs approximately 17.6 pounds.
The clock operated for a hundred days and more at a single winding,
according to Father Borghesi, and by means of a pendulum with a leaden
bob weighing 60 Viennese pounds, attached at a height of 5 feet. Father
Borghesi stated the weight of the pendulum to be 60 _librarum
Viennensium_, but the Viennese libra does not appear among the weights
of the Austrian Empire. However, using the average libra, an ancient
Roman unit of weight equal to 0.7221 pound, it may be assumed that the
driving weight should be approximately 45 pounds.
Father Borghesi, however, does not venture to provide any description
whatsoever of the movement of his second clock in his book. He gave the
following reasons:
But beyond this, I entirely omit [a description of] the further
apparatus of the very many wheels, etc., inside the clock which
carry on its functions, lest I become too verbose for some
persons. To explain more thoroughly the internal labyrinth of
the entire mechanism, from which the movement of the circles or
heavens, etc., are derived, would seem to entangle in too many
complicated perplexities.... Therefore, that I might not delay
longer, and perhaps to no purpose, I have thought it better to
leave the whole work to the proportionate calculus of the
arithmeticians and the technical skill of mechanics. If they
have any desire to construct a similar mechanism, they will
follow the aforesaid motions of the heavens, etc., not only by
one means alone but by many, more swiftly through thoughtful
study than by any amount of instruction.
For whoever is well versed in the theory of calculus and sets
to work at any given project, will discover any desired motion
by a thousand and more ways, by one or another gearing of
wheels; which an industrious mechanic will carry out in
actuality and without too much difficulty. Nor is there any
reason for anyone to be discouraged, so long as he is not
disgusted by the amount of labor for there is nothing truer
than the old saying "The favorable gods grant everything to the
assiduous laborer."
Nay, further, even this little work itself can be improved on
and surpassed by new inventions. Otherwise that other old
adage, almost as old as the world, would prove false, "What you
have found already done, you can easily repeat, nor is it
difficult to add to what has already been invented." Relying on
this principle, I have already conceived some new things to be
added to the present little work.
[Illustration: Figure 17.--MOVEMENT OF BORGHESI CLOCK viewed from the
right side, with details of chiming mechanism.]