I have read many books and many articles and letters in newspapers and scientific periodicals advocating the compulsory use of the metric system, optional amongst us since 1897, but which no trade, industry or profession will adopt, and I have almost invariably found that the writers knew the metric system imperfectly, and always that they knew their own very badly. I have found their advocacy illustrated by examples of problems in imperial weight and measure which showed defective instruction in the art of cyphering and supported by statements which were misleading and only to be charitably excused on the ground of ignorance.[59] Too often opponents of their propaganda are sneered at as wanting in scientific knowledge, business experience, and common sense. Footnote 59: For instance, in _The Coming of the Kilogram_ (H. O. Arnold-Forster) the problem ‘How many times is 1 grain contained in 1 ton?’ is worked out in a half-page of figures. It can be done in 15 seconds, almost mentally. A cwt. is 112 lb.; a ton is 2240 lb.; multiply by 7000. Answer: 15,680,000 grains (or times). The propaganda of the metric system is effected, from abroad by diplomacy, and from within by— 1. Calling it ‘antiquated,’ a term which might be applied to Law, to Religion, to Marriage, to Property, and other ancient institutions. 2. Calling it ‘irrational,’ when it has that great reason which comes from custom, convenience, improvement in recent times. 3. Calling it ‘unscientific,’ when it joins to popular convenience the option of decimalisation, whenever that is found convenient, in addition to the alternate decimalisation already established in several series. 4. Putting forward as current certain weights, such as the Troy pound, long ago obsolete. 5. Putting forward as legal measures trade-units, such as the cask, the sack, &c., used for convenience in trade, as much in metric countries as with us.[60] 6. Putting forward, as necessary, sums and calculations which a decently taught schoolboy would laugh at. 7. Ignoring all that is convenient in our system and all that is inconvenient in the metric system. 8. Ignoring the satisfaction of the people of the United States with our system, even when retaining the old wine-gallon and corn-gallon. 9. Ignoring the resistance of the French people to the metric system after a century of education in it and of police-constraint. 10. Urging us to follow the example of other countries that have adopted it, but omitting to find out whether the peoples of these countries, from civilised Germany to barbarous Haïti, use it—so far as they do use it—otherwise than under compulsion. It is the governments of these countries, not the people, that have adopted it, always in the name of Science; and the day police-pressure were taken off, the old system would return, or, at the least, the decimal series would disappear.