II. That its parts and multiples be in _an easy proportion_ to each other, so as to facilitate the money arithmetic. III. That the Unit and its parts, or divisions, be _so nearly of the value of some of the known coins_, as that they may be of easy adoption for the people. The Spanish Dollar seems to fulfil all these conditions. I. Taking into our view all money transactions, great and small, I question if a common measure of more _convenient size_ than the Dollar could be proposed. The value of 100, 1000, 10,000 dollars is well estimated by the mind; so is that of the tenth or the hundredth of a dollar. Few transactions are above or below these limits. The expediency of attending to the size of the money Unit will be evident, to any one who will consider how inconvenient it would be to a manufacturer or merchant, if, instead of the yard for measuring cloth, either the inch or the mile had been made the Unit of Measure. II. The most _easy ratio_ of multiplication and division, is that by ten. Every one knows the facility of Decimal Arithmetic. Every one remembers, that, when learning Money-Arithmetic, he used to be puzzled with adding the farthings, taking out the fours and carrying them on; adding the pence, taking out the twelves and carrying them on; adding the shillings, taking out the twenties and carrying them on; but when he came to the pounds, where he had only tens to carry forward, it was easy and free from error. The bulk of mankind are school-boys through life. These little perplexities are always great to them. And even mathematical heads feel the relief of an easier, substituted for a more difficult process. Foreigners, too, who trade and travel among us, will find a great facility in understanding our coins and accounts from this ratio of subdivision. Those who have had occasion to convert the livres, sols, and deniers of the French; the gilders, stivers, and frenings of the Dutch; the pounds, shillings, pence, and farthings of these several States, into each other, can judge how much they would have been aided, had their several subdivisions been in a decimal ratio. Certainly, in all cases, where we are free to choose between easy and difficult modes of operation, it is most rational to choose the easy. The Financier, therefore, in his report, well proposes that our Coins should be in decimal proportions to one another. If we adopt the Dollar for our Unit, we should strike four coins, one of gold, two of silver, and one of copper, viz.: 1. A golden piece, equal in value to ten dollars: 2. The Unit or Dollar itself, of silver: 3. The tenth of a Dollar, of silver also: 4. The hundredth of a Dollar, of copper. Compare the arithmetical operations, on the same sum of money expressed in this form, and expressed in the pound sterling and its division.