#<- this is why Prieur became a regicide /s

[aedesluminis]

Letter from Claude-Antoine Prieur to Louis XVI on the importance of having a unified metric system in France

[The letter is dated April 1790 and included a copy of Prieur's Mémoire sur la nécessité et les moyens de rendre uniformes, dans le royaume, toutes les mesures d'étendue et de pesanteur]

"Sire,

The reputation that your Majesty has gained through his passion for sciences and the protection with which he has constantly provided them inspired in me the desire to offer him a work I have done on the necessity and the means to bring all measures of France to uniformity.

I beg your Majesty to honour me for a moment of his attention, not much for some special merit concerning my work, but above all for the high importance of its content.

It is a great and beautiful idea, the one of giving to a great people a common and invariable measure, and, even better, to make it universal. Today, the difficulties related to the lack of precision in the procedures have been overcome; what is left is just a few prejudices relegated to the classes of ignorant people, of whom the triumphant voice of reason will dismiss the prestige.

France, England, the United States of America have addressed the matter not only in their own countries, but they are in open agreement to achieve an identical result.

Savants are rather convinced of the effectiveness of this operation for the advancement of science; but how much it will reveal itself useful in easing commercial relations, from the simplest exchanges, which people’s daily needs require, to the greatest speculations!

From this double perspective of science and commerce, the States of your Majesty maintain a distinguished position among civilised nations. After all, wisdom, moderation, in a word, all the virtues of your Majesty, suggest on his part an aspiring desire towards the noble glory of being included among the benefactors of humankind. May I be allowed to say that this is a fortunate occasion to add a new benefit to those that your subject already owe you: the reunion of your Majesty with other countries to procure the same measures would be a big improvement  and a favourable wish for the happiness of the people; nothing is more appropriate to strengthen in them the bonds of fraternity and concord like the sweet influence of Philosophy.

Respect has set limits that I am not entitled to go beyond. Nevertheless I thought to let truth arrive to the ears of a prince, who, because of his greatness of spirit, has always proven himself worthy of listening. To touch the heart of your Majesty, it is undoubtedly sufficient to mention a useful purpose: it will be even more touched to know that the probity, of which the operation in question is significantly the custodian, will put an end to the activities and tricks of the scoundrels.

I have persuaded myself that my disinterested homages would not be unpleasant; I am, with the utmost respect, your Majesty’s most humble and obedient servant."

— from G. Bouchard, Prieur de la Cote-d'Or, Pièces Annexées, p. 458 - 459