3280 Metrics and Morals! DB at his best
austraLasia #3280

 

Metrics and Morals! DB at his best

5 September 2013 -- A boy in Don Bosco's class would have known, from the chapter on 'Subtraction' in his textbook, that you can't take 5 apples from 6 pears, because his teacher, who wrote the textbook, had told him that "just as numbers of different species cannot be added, nor can they be subtracted". Mind you, many of the boys in that class might have thought to themselves: "Yes, but I can certainly take five apples from three of the neighbour' trees!"  Not so fast - the textbook possibly had an answer to that one too, since not a few of its examples also involved a moral lesson. Metrics and morals! Like one of the exercises on multiplication: "A boy spends 2 francs a week on tobacco and 5 on billiards. How much would he save in a year if he abstained from these vices?"

Welcome to "The Arithmetic and Metric Decimal System Made Simple.....", 7th edition.  For the first time in English. This textbook from Don Bosco's hand is a real charmer. You may even learn something as you read it!  Did you know that the unit of length (metre) was based on the earth, while the unit of weight (gram) was based on water?

Napoleon's invading armies and various annexations of territory to the French Empire had ensured the introduction of the metric system which they had 'invented' or at least systematised. But it was unpopular with the masses and there was resistance. In fact during the Restoration much of Italy had abolished it.  But in 1845 the Kingdom of Sardinia and Piedmont issued a special decree - 11th Spetember 1845, (so we are almost at the 168th anniversary!) - to reintroduce it, making it obligatory by 1850.  It was during these five years that Don Bosco got to work on his textbook - 1846 the first edition, 1849 the second edition. His aim was to ensure that the ordinary people, especially rural folk and his boys who could be manipulated by dishonest employers, could be true citizens and share in social and economic life. This textbook, which by its final edition included arithmetic, the metric system, geometry, solid geometry, and conversion charts, was one of his ways of doing it. As he points out in it: "The diversity of weights and measures is open to error and unfair manipulation".

The approach Don Bosco adopted is typical of him: dialogue form, Q&A. When he gets to the 'decimal' part (after explaining to his readers what a base ten system is, a base twelve, and so on), there are a few measures that we might not recognise today, though we can work most of them out: we don't use the myriagram (though we know that myriads of things are plenty indeed), and we might have problems with the stero (cubic metre), but we can work out the ara 100, sq. metres because we have hectares today. Hectare was not a measure in use then, but had Don Bosco wanted to include it, his dialogue would have continued something like this:
Q: How big is a hectare?
A: 10 000 square metres.
Q: How big is that?
A: It is the equivalent of a square, each side having a length of 100 m.  etc.

You will discover some interesting supplementary knowledge: from his examples you get an idea of Turin's population, will know (if you didn't already) that Arabic numerals are also called Indian, because it is possible the Arabs got them from India. You will see that as well as boys saving money on vices, good citizens put aside money to restore churches and give alms to the poor.

The texbook includes only serious stuff - the metric decimal system was not something to joke about - not for the textbook at least, but he did have some fun with it by writing a short comedy on the topic (translation not available as yet). His good friend Ferrante Aporti claimed this was a stroke of genius - getting people to learn while they laugh!

Which probably allows us to end on a lighter note.  After reading this textbook, do you still have trouble with metric conversions?  Try learning them this way:

1 million microphones = 1 megaphone
2000 mockingbirds = two kilo-mockingbirds
10 cards = 1 decacards
1 millionth of a fish = 1 microfiche
1/1000 mentals = 1 centimental
1 trillion pins = 1 terrapin
10 rations = 1 decoration
10 millipedes = 1 centipede
2 monograms = 1 diagram
2 wharves = 1 paradox
1 billion questions = 1 giga-what
And then there's the one about a certain American President who was distraught when he heard that 3 Brazilian soldiers were killed in Baghdad. "My God!", he cried."How many in a Brazillion?"