H. T. C., Biz and J. A. M.—Candidates for clerkships in the government departments must pass a civil service examination in arithmetic, geography, grammar, history, reading, writing and spelling, and in some cases a knowledge of book-keeping is required. This depends upon the branch of the service and the special position for which application is made. Those desiring to enter the railway mail service must, among other things, give the boundaries of their own county, State and country; the location of all the States and Territories, locate all the counties along a specified mail route, locate offices on the route and exhibit a thorough understanding of the geography of the United States.

Frank W.—1. According to Cæsar, the first coins of what is now called Great Britain were of tin, and he has been substantiated by the discovery of pieces made of that material. The first copper coins made by the United States Mint were one cent and one-half cent pieces, of which there were four designs, designated the "chain cent," the "wreath cent," the "flowing-hair cent" and the "liberty cap cent." 2. The letter, or mark on a coin designating the mint at which it was struck, is called the "mint mark." The U. S. coins struck at the parent mint, at Philadelphia, bear no such mark; those displaying a small "S" immediately under the denomination are coined in San Francisco, while "C. C." stands for Carson City, and "O" for New Orleans.

Ex-Confed.—A glue well adapted for any work which requires particular strength is made by dissolving an ounce of the best isinglass, by the application of a moderate heat, in a pint of water. After straining this solution an ounce of the best glue, previously soaked in water for twenty-four hours, and a gill of vinegar should be added. After all of these materials have been brought into a solution, the mixture should be allowed to boil up once, and then the impurities must be strained off. A handy method of making glue for ready use is to employ common whisky instead of water in dissolving any quantity of glue. Put both together in a bottle, cork it tight and let it stand for three or four days, when it will be ready for use without the application of heat.

Birdie Haight.—1. The American swan breeds in the northern parts of America, and its migrations extend only to North Carolina. Another American species is the Trumpeter Swan, breeding chiefly within the Arctic Circle, but of which large flocks are seen in winter as far south as Texas. It is smaller than the common swan, which is found in its wild state in Asia and the eastern parts of Europe. In a half-domesticated state it has long been a common ornament in lakes and ponds in this country and Europe, more especially the latter. The black swan is a native of Australia. 2. Varicose veins, it is said, may be radically cured by a surgical operation, but the disease may reappear in some other portion of the body, there being no way to prevent it. 3. Papua, or New Guinea, is the largest island in the world. Australia now ranks as one of the grand divisions of the earth.

S. A. M.—Eighteen articles on electricity have been published in this and previous volumes. They were: "A Cheap Electrical Machine," Vol. II, No. 22; "How to Make a Simple Electrical Machine," Vol. VI, No. 3; "Experiments of Various Kinds," Vol. VI, No. 4; "A Storm in a Teacup," Vol. VI, No. 9; "The Leyden Jar and How to Make It," Vol. VI, No. 20; "The Electrician at Home," Vol. VII, No. 16: "A Mysterious Alarm," Vol. VIII, No. 14; "Studies in Static Electricity," Vol. IX. No. 30, "How to Make an Electrical Machine," Vol. IX, No. 20; "How to Make an Electric Battery," Vol. X, No. 8; "The Induction Coil and How to Make It," Vol. X, No. 28; "A Simple Electrical Machine," Vol. XI, No. 6: "Simple Electrical Experiments." Vol. XI, No. 15; "An Electric Bell Outfit," Vol. XI, No. 20; "How to Make a Storage Battery," Vol. XI, No. 25; "Induction Coil Condenser," Vol. XI, No. 47; "Electric Lamps and How to Work Them," Vol. XII, Nos. 1 and 2; and "Electro-Motors and How to Make Them," Vol. XII, No. 3.

Bias Eyes.—1. Letters relating to business matters connected with this paper—such as inquiries relating to advertising rates—are the only ones answered by mail. They must invariably contain a stamp to pay postage on such reply. 2. Any reader complying with the rules governing the exchange department is entitled to its privileges. 3. He is an Englishman by birth. 4. The principal use of the bell on board ships is to denote the time of the day or night, which is done by 1, 2, 3, and so on, up to eight strokes of the bell. The twelve hours between midnight and noon, or noon and midnight, are divided into three portions of eight bells each, the duration of time between bells being half an hour. Consequently, during the course of each twelve hours, the same number of strokes of the bell will necessarily be used to denote three different hours or periods of time, as follows:

1 bellat12.30,4.30,8.30.
2 bells"1.00,5.00,9.00.
3 ""1.30,5.30,9.30.
4 ""2.00,6.00,10.00.
5 ""2.30,6.30,10.30.
6 ""3.00,7.00,11.00.
7 ""3.30,7.30,11.30.
8 ""4.00,8.00,12.00.

5. The magnetized needle of a compass has the property of arranging itself in the meridian, one end always pointing to the north and the other to the south; yet not exactly, but with a deflection or declination which varies from time to time in magnitude, and may be toward the west or the east.

A Reader of Golden Days. A very plain and simple method of making snow-shoes was furnished our readers in Vol. Vll, No. 2. —Rod and Gun. In Nos. 15, Vol. I; 23, 24 and 36, Vol. II, will be found articles devoted to the subject of camping out, which contain all requisite information regarding that form of recreation. —Dody. The Spanish sentence is untranslatable, several of the words being beyond the ken of any one who understands that language. —Lawyer. The gentleman representing your district in Congress is the proper person to whom application should be made for copies of the "Congressional Record" and Department Reports. —J. S. T. A portion of No. 52, Vol. VIII, was devoted to a minute description of ice-boat building. —A. S. 1. California half-dollars, in perfect condition, are worth 60 or 70 cents each. 2. It is claimed to be very efficacious. —W. P. Your offer is respectfully declined. We have already provided many articles on electricity in its various forms, and from time to time will publish others by practical writers. —Nena. 1. The titles of the serials in the volumes named are printed in the index furnished with each. 2. Harry Castlemon was the author of "The House-Boat Boys." —Constant Reader. We never supply business addresses. —Jim. Not possessing the key we are unable to solve the cryptogram. —L. F. It is a very interesting game, suited to the tastes of both old and young. The query was sent too late to be answered in the Christmas Issue. —Byron V. Refer the matter to a local engineer. —Howard W. E. A description of the way to make a small storage battery appeared in Vol. XI. No. 25. —Constant Reader. Books devoted to hypnotism have been written by Drs. Hammond, Bernheim, Moll and Raue, besides which it has formed the subject of many magazine articles. —Wheelman. Read the description of electroplating in Vol. XI, No. 23. —J. L. J. No premium. —W. K. 1. We do not pay for contributions to "Puzzledom." 2. All the stories, sketches, etc., published in these columns are written by experienced authors. —O. J. C. U. 1. The papers are mailed from this office on Friday night. 2. Yes; in any sum less than one dollar.