Appendix B: Tito Livio Burattini's catholic meter

Among the several scientists that advocated the seconds pendulum as unit of length it is worth to emphasize the figure of Tito Livio Burattini, an unusual and interesting personality of the 17th century,⁴⁷and his Misura Universale, published in 1675 [49]. Apart from issues of priority on the proposal of the seconds pendulum as unit of length, to which we are not interested, the historical relevance of Burattini's work resides mainly in the several modern concepts and nomenclature that appeared for the first time in his book. The most relevant of them is the idea of relating different units via physical quantities in order to set up a complete system starting from the unit of time. The sub-title in the front page of his document accounts for his ambitious proposal:

Treatise in which it is shown how in every Place of the World it is possible to find a UNIVERSAL MEASURE & WEIGHT having no relation with any other MEASURE and any other WEIGHT & anyway in every place they will be the same, and unchangeable and everlasting until the end of the WORLD.''⁴⁸

Here the word universal is used for the first time for a unit of measurement. In the 9th page of his document (pages are unnumbered) he makes the suggestion to call metro cattolico (catholic meter -- `catholic' in the sense of universal) a standard realized by the pendulum:

So, Pendula will be the basis of my work, and from them I shall first originate my Catholic Meter, that is the universal measure, as I think I have to name it in Greek, and then I shall originate a Catholic Weight from it.''⁴⁹

Here is finally, in the 20th page, his definition of the meter:

The Catholic Meter is nothing but the length of a Pendulum, whose oscillations are 3600 in a hour

[...]

as I refer to a free Pendulum, and not to those which hang from Clocks.⁵⁰

We think Burattini would be very pleased to learn that the unit of length of the International System differs from his meter by only half centimeter!