It might afford our readers some pleasure to know that this work is entirely Australian. The printers, artist, and author are all colonial-born, and the production of the former two, at any rate, will compare favourably with that of any others. The engravings throughout have been in the hands of Mr. Murray Fraser and staff, whose experience in this special art has tended to make the book more attractive than it otherwise would have been. The author is not above receiving any suggestions or contributions in the way of peculiar puzzles or commercial comicalities, which might enhance the value of the book. Intending contributors are invited to communicate to the address given below, and can rest assured that they will be remunerated according to the merits of their communications. THE AUTHOR. _44, Pitt Street, Sydney._ _Refer to Appendix for Answers to numbered Problems._ READING BIG NUMBERS. Wonderful Calculations. Although we are accustomed to speak in the most airy fashion of millions, billions, &c., and “rattle” off at a breath strings of figures, the fact still remains that we are unable to grasp their vastness. Man is finite--numbers are infinite! ONE MILLION Is beyond our conception. We can no more realise its immensity, than we can the tenth part of a second. It should be a pleasing fact to note that commercial calculations do not often extend beyond millions; generally speaking, it is in the realm of speculative calculation only, such as probability, astronomy, &c., that we are brought face to face with these unthinkable magnitudes. Who, for instance, could form the slightest idea that the odds against a person tossing a coin in the air so as to bring a head 200 times in succession are 160693804425899027554196209234116260522202993782792835301375 (over I decillion, &c.) to 1 against him? Suppose that all the men, women and children on the face of the earth were to keep on tossing coins at the rate of a million a second for a million years, the odds would still be too great for us to realise against any one person succeeding in performing the above feat, and yet the number representing the odds would be only half as long as the one already given. Or, who could understand the other equally astounding fact that Sirius, the Dog-star, is 130435000000000 miles from the earth, or even that the earth itself is 5426000000000000000000 tons in weight. WHAT IS A BILLION In Europe and America, the billion is 1,000,000,000--a thousand millions--but in Great Britain and her Colonies, a billion is reckoned 1,000,000,000,000--a million millions: a difference which should perhaps be worth remembering in the case of francs and dollars.