PREFACE. THE Metric System of Measures and Weights, owing to its extreme simplicity, the facilities afforded in calculations by its complete decimal character and consequent freedom from the labour of converting one denomination into another, has been adopted by most of the Continental nations and their colonies. Through various treaties of commerce between our country and the above nations, our trade and commerce with them are rapidly increasing; a series of Tables therefore, for facilitating the ready conversion of their Measures and Weights into those of the British Standard, and vice versa, will render important service to all engaged with those countries in manufacturing, mechanical, or commercial transactions. These Tables were, in part, originally calculated for my own use while professionally engaged on the Continent; I have, however, been induced to extend them so as to form a complete collection, including all British legal denominations of measure and weight. The Data for the Tables have been deduced with the greatest care from the primitive equivalents determined by the Commissioners appointed by the State to conduct experiments for the purpose; in every case a large number of decimals have been taken, in order that the results, when carried forward into a practical form, may be true to the last figure. The fractions of the lowest denominations give in the Tables are decimal, and carried to three places or thousandths, as deemed sufficient for all practical purposes. I am indebted to G. B. Airy, Esq., F.R.S., Astronomer Royal for his kindness in having examined the fundamental numbers upon which the Tables have been calculated, and having certified to their correctness. Also to James Yates, Esq., F.R.S., of Lauderdale House, Highgate, near London, Vice-President of the International Decimal Association, to whose valuable researches on the subject of metrology and exertions in favour of the Metric System, the promoters of the Bill for legalizing the use of the Metric System in England, may attribute its success in passing through the House of Commons. LONDON, June, 1864. C. H. DOWLING. ADVERTISEMENT TO THE SECOND EDITION. THE Author of this work, a peaceful Englishman, never having borne arms, and long resident in Paris, having been arrested by the Germans in his attempt to quit that city, during the siege in the winter of 1870-1, was sent by them, as a Prisoner of War, to the Fortress of Stralsund in Pomerania, where he succumbed to the privations and exposure he suffered there, and on his compulsory journey thither; therefore the revision of this edition, though performed by fully competent hands, is not the work of the lamented Mr. Dowling. LONDON, Sept., 1872. |