It would be impossible to give a complete list of the subjects that might be fairly classed under Mechanical Puzzles. What is a puzzle to one generation is none to the next, and so on; new puzzles are constantly being invented and found out. There are a few old ones around which a considerable amount of interest must centre because of their intrinsic merit, and which should find a place in every book prepared for the amusement and recreation of youth; there are also new ones not yet much known, which should be mentioned more because of their newness, perhaps, than their merit.

BALANCING PUZZLES.

A few Balancing Puzzles have been included in the section allotted to Toy Games and Toy-making; for inasmuch as a certain amount of making was necessary, it seemed proper to place them there, and it is sufficient now to refer the reader to that section for some varieties in Balancing Puzzles that are not to be found here.

The Balanced Pail (Fig. 1.)—To balance a pail suspended by its handle on a stick, less than half of which rests on its support, would seem to be an impossible feat. It is to be done, however, if the following instructions be carefully followed:—Take a stick (C D), over which the handle of the bucket or pail is to be placed, and place the stick about two-fifths of its length on a table (A B). The handle of the pail should be so placed over the stick as to be in an inclined position shown by the letters H I, and so that the edge of the pail may touch the edge of the leg or side of the table. To make the pail retain its position, another stick (E F G) will be required, the one end of which should reach to the bottom of the pail, the other end being fitted into a notch previously cut at the point E, in the first stick (C D). The stick (E F G) should rest on the edge of the pail at the point F. The bucket will thus be kept safely balanced, and may, provided the sticks are fairly strong, without risk be filled with water.

The Balanced Stick.—A stick may be balanced and made to stand upright on the top of the finger by first taking the precaution to insert into its upper end, at about half an inch from that end, two knives, or two forks, or two other articles of equal weight. The stick should be of such a length that the ends of the knives are a trifle lower than the end of the stick when balanced.

A similar puzzle is to make a coin turn on its edge on the point of a needle, or to make a needle turn on its point on the head of a pin. For either of these puzzles, get a bottle, cork it tightly, and in the cork (which we will name B) place a needle or a pin; then take another cork (which we will call X) and cut a slit in one of its ends, so that the coin to be balanced will fit into the slit. If it is on a needle that the coin has to be balanced, force the needle into the cork B point outwards. Now stick two common steel forks, one on either side, into cork X, so that the forks hang downwards; place the coin in the slit of the last-mentioned cork and the edge of the coin on the point of the needle. If the needle is to be balanced on a pin, place the needle in the same manner; the weight of the forks will keep the toy balanced, and enable it to be safely spun round without danger of falling.

The Bridge of Knives (Fig. 2).—Three knives may be supported by their handles on the rims of three cups or glasses in the following manner:—Place the glasses in a triangle, each side of which shall be about equal in length to one of the knives to be balanced. The blade of the first knife should rest on the blade of the second by passing over it near to the point where the handle and blade are joined, the blade of the second passing in the same manner over the blade of the third, which is to be made to rest on the blade of the first. The handles being then properly placed on each one of the glasses forming the triangle, the bridge will be made, and it will be strong enough to bear a considerable weight.

THE SQUARE AND CIRCLE PUZZLE.

Cut a square piece of cardboard, marked as shown in Fig. 3, into four pieces of equal size and similar shape, so that each piece shall contain three of the marks, and so that none of the marks are cut. Fig. 4 shows that the puzzle is solved by cutting the lines A from a quarter down on the left-hand side to half-way across, then down through the middle to three-quarters of the distance from the top, and then along to the opposite side of the card. The line B takes a corresponding course, being commenced on the top line at a quarter of the whole distance from the right-hand side.

THE CARPENTER'S PUZZLE.

This is very similar to the above. A carpenter had to mend a hole in a floor which was two feet wide and twelve feet long. The board given him to mend it with was three feet wide and eight feet long. He was instructed to entirely cover the hole, to allow no part of the board to overlap, and he was allowed to cut the board into two pieces only. He accomplished the feat by cutting the board as shown by the dotted lines in the annexed Fig. 5, and joining them over the hole in the floor in the manner shown in Fig. 6.

THE DIVIDED FARM.

This is a still more complicated puzzle of the same description. It is the last of the sort we shall give, but many more of a like character may be constructed. A Frenchman died leaving five sons, among whom he had expressed a wish to divide his farm, on which ten trees grew, so that they all might live together in the house (represented by the dark square in the diagrams), and so that each might have an equal share of land, of a similar shape, each share having two trees growing upon it. Fig. 7 shows the land before it was divided; the lines in Fig. 8 show how the fences were put up when the old man's wish had been carried out.

THE VERTICAL LINE PUZZLE.

This puzzle is very old; but, although simple, is very good. It may be treated either as a mechanical or as an arithmetical puzzle. Place six narrow strips of cardboard of equal length in a row, and add five other pieces in such a way that the whole form nine only. The result is shown in the second row of lines, the added pieces being represented by the dotted lines (Fig. 9). This puzzle may be said to be only a play upon words, but in most puzzles there is some catch.

THE STRING AND BALLS PUZZLE.

Get a thin piece of wood, bone, or ivory, of the shape shown in the annexed figure (Fig. 10); bore in it three holes—one at each end, and one in the middle. Pass a piece of string or twine through the middle hole, leaving a loop, as shown; on each side of the string thread a ball or ring, and fasten the two ends of the string with knots at the holes at the end of the piece of wood. The puzzle is, without removing the string from the holes or without untying the knots, to get both balls or rings to the same side of the central loop instead of on opposite sides. The following is the solution of the puzzle:—Draw the central loop of the string well down, and slip through it either one or other of the balls until it reaches the back of the central hole; then pull the loop through the hole, and pass the ball through the two loops that will thus be formed; draw the string back through the hole as before, and the ball may easily be passed to that part of the string on which the other ball has been strung. This plan of passing the loop through the central hole is a key to all the puzzles of this nature. Such puzzles appear under various names, but they may all be solved if the key to this puzzle of the Balls and String is borne in mind.

A somewhat similar, although more complicated puzzle, is that known as

THE PUZZLING RINGS.

This name, by the way, describes the puzzle, but it has been so many times christened, that no list of names could claim to be a complete list. The puzzle is smart and neat, but the parts have to be so nicely fitted, that it would not be easy for an amateur to make it. It may be purchased at a small cost at any toy-shop. The following is its description:—In a flat board of wood, bone, or metal are a certain number of holes—more or less, according to the size of the puzzle. In each hole a wire is loosely fixed, beaten out into a head at one end, to prevent the wire slipping through the hole; and the other end is fastened to a ring, which is also loose. Each wire has been passed through the ring of the next wire previously to its own ring being fastened on; and through the whole of the rings runs a wire hoop or bow, which also contains, within its oblong space, all the wires to which the rings are fastened, the whole presenting so complicated an appearance as to make the releasing the rings from the bow seem to be an impossibility. The puzzle, nevertheless, is to take off the rings.

The following is the plan to be followed:—The instructions given are for removing the rings from a seven-ring puzzle (Fig. 11), that being the simplest form in which the puzzle is made; but it should be noted for general guidance that if an even number of rings are on the bow, the first and second are to be brought down together; if odd, the first one only. To proceed:—Take the hoop in the left hand, and hold the puzzle so that the first ring to be taken off is at the end farthest away from that hand. Draw down the first ring from the bow, and drop it down through the bow, so that it may be between the board and the bow; proceed similarly with the third ring; replace the first, by passing it up through the bow; bring it (the first) to the end of the bow, bearing in mind that the wires supporting the rings must be perpendicular between the two sides thereof; bring down the rings 1 and 2 together; then bring down No. 5; take up 1 and 2 together; bring down 1; take up 3 and 1; bring down 1 and 2 together; bring down 4; take up 1 and 2; bring down 1 and 3; take up 1; bring down 1 and 2 together; and bring down 7; which completes the seven-ring puzzle.

To put the rings on again:—Put on 1 and 2; bring down 1; take up 3; and then 1; bring down 1; and so on, always taking up the first or outward rings.

The seven-ring puzzle is, as already stated, the simplest of these puzzles, as the ten-ring puzzle is usually the most complicated. To perform the ten-ring puzzle it has been computed requires no less than 681 moves. The instructions given above apply equally well to both, if only the note as to an odd or even number of rings to be removed is remembered.

The puzzle of the Balls and Rings (Fig. 12) has points of similarity with the above, and also with that of the string and balls puzzle. The balls and rings puzzle is very ingenious, and should be asked for at the toy-shop. It consists of a round frame of mahogany, about two inches in width and a quarter of an inch thick. In this frame, and at regular intervals, are holes, between which are placed, on the one side of the frame, rings, and on the other side, balls. The rings and balls are made fast with a cord, which passes through each ring and each ball, and also through all the holes in the frame, the ends of the cord being tied in a cross. The puzzle is to reverse the position of both the rings and the balls from one side of the frame to the other.

As indicated in the String and Balls puzzle, the key to this and similar puzzles is to be found in a loop of string, which is usually concealed in some part of the puzzle. The loop should be pulled out or through the wood, and passed over the ball nearest to it; the solution of the puzzle will then be apparent.

THE STAFF PUZZLE, THE VICTORIA PUZZLE, AND THE ARTILLERY PUZZLE.

These are all ingenious puzzles of this class, introduced by Mr. Cremer, of Regent Street, who issues the keys for the solution of the puzzles with the toys.

THE SIX ROWS PUZZLE.

Place twelve counters in six rows in such a manner that there shall be four counters in each row. Fig. 13 shows how the puzzle is solved.

THE SIX SQUARE PUZZLE.

Place twelve counters on a piece of slate or cardboard, so that they would be at the angles of six squares, as shown in M, in the accompanying diagram (Fig. 14). The puzzle then is to take away three counters, so that the remaining nine counters shall describe three squares only. The solution is shown in N, Fig. 14. The twelve counters form the six squares A, B, C, D, E, F, whereas upon the counters 1, 2, and 12 being removed the squares C, D, and E only are left.

THE MAGIC OCTAGON.

Out of a piece of stiff cardboard, cut four of each of the three designs shown in Fig. 15, A, and so join them together that they form an octagon figure. The pieces numbered 1 are to be fitted together in the centre, the pieces 2 and 3 being placed alternately round the pieces numbered 1, after those pieces have been fitted together (Fig. 15, B).

THE ACCOMMODATING SQUARE.

Cut out eight squares of cardboard; divide four of them into halves, cutting them from corner to corner, so that there are in all twelve pieces. The puzzle is to form a square with the twelve pieces. It is to be done as shown in the accompanying plan. The four squares and the eight triangular pieces are numbered respectively 1 to 4 and 5 to 12 (Fig. 16).

THE MAGIC CROSS.

Take three pieces of cardboard of the shape of the figure numbered 1 in Fig. 17, A, and one piece each of the shapes of 2 and 3. The pieces may be of any size, but it is hardly necessary to say that relatively each one must correspond with the sizes and shapes indicated in the diagram. Fig. 17, B, shows the pieces when put together and forming the cross.

TO TAKE A MAN'S WAISTCOAT OFF WITHOUT REMOVING HIS COAT.

This puzzle is almost good enough to be included among conjuring tricks, but as there is neither magic nor sleight of hand involved, there is no alternative but to place it here. The puzzle seems ridiculous and unreasonable, as in performing it neither the coat nor vest may be torn, cut, or damaged, nor may either arm be removed from the sleeve of the coat. The puzzle cannot always be performed, as it depends upon the size of the coat-sleeves allowed by the fashions of the day, though as a rule a coat with suitable sleeves will be found in most households. The person whose waistcoat has to be removed should be the wearer of a coat the sleeves of which are sufficiently large at the wrist to admit of the hand of the operator being passed up and through them. Any person undertaking to perform the puzzle in a drawing-room should first request some one of the company to remove his evening coat, and to replace it by a light spring overcoat; this being done, it will be easy to carry out the following instructions: The waistcoat should first be unbuttoned in the front, and then the buckle at the back must be unloosed. The operator, standing in front of the person operated upon, should then place his hands underneath the coat at the back, taking hold of the bottom of the waistcoat, at the same time requesting the wearer to extend his arms at full length over his head. Now raise the bottom part of the waistcoat over the head of the wearer (if the waistcoat be tight it will be necessary to force it a little, but this must not be minded so long as the waistcoat is not torn); the waistcoat then will have been brought to the front of the wearer, across his chest. Take the right side bottom-end of the waistcoat, and put it into the arm-hole of the coat at the shoulder, at the same time putting the hand up the sleeve, seizing the end, and drawing it down the sleeve; this action will release one arm-hole of the garment to be removed. The next thing to be done is to pull the waistcoat back again out of the sleeve of the coat, and put the same end of the waistcoat into the left arm-hole of the coat, again putting the hand up the sleeve of the coat as before, and seizing the end of the garment. It may then be drawn quite through the sleeve, and the puzzle is accomplished.

TO BREAK A STONE WITH A BLOW OF THE FIST.

To do this two stones are required, each one of which should be from three to six inches in length, and about half as thick. Place one of the stones flat, firmly and immovably, upon the ground, and on it place one end of the other stone, raising the opposite end to an angle of something like forty-five degrees, and just over the centre of the lower stone, with which it must form a T, being kept in that position by a piece of twig or stick of the necessary length. The top or elevated stone should then be smartly struck at about the centre with the little-finger side of the hand; the stick, of course, will give way, and the bottom stone will be broken to pieces.

THE KEY, THE HEART, AND THE DART.

This is a very old-fashioned puzzle, and easy of accomplishment to those who know how to do it. The puzzle is either to arrange the three articles in an apparently inextricable manner, or, if they are so arranged, to separate them without damaging either, or bending the cardboard out of which they should be made.

Cut out of some tough and elastic cardboard a double-headed dart, a key, small at the ring end, and a heart, in which should be cut four angular slits, shaped as in Fig. 18. To arrange them together, the lowermost cut in the heart must be pressed out so that it will form a loop, through which the ring end of the key has to be drawn, and so that one end of the dart may also be passed through without breaking the cardboard. Then fold the dart in the middle, so that one of its heads shall accurately fit upon the other head; bring the loop of the heart back into its former position, drawing it out of the ring of the key, which should then glide down the shaft of the dart, and hang fast held by the head. To disentangle the articles, reverse the order of procedure.

THE PRISONERS' RELEASE PUZZLE.

Take two pieces of string or tape, and round the wrists of two persons tie the string, as shown in Fig. 19. It adds to the amusement of the puzzle if one of the persons is a lady and the other a gentleman. The puzzle is for them to liberate themselves, or for any one else to release them without untying the string. To do this, B makes a loop of his string pass under either of A's manacles, slips it over A's hands, and both will be free. Reverse the proceeding, and the manacles are again as before.

As a finish to the Mechanical Puzzles, we will give the key to the world-renowned

HAMPTON COURT MAZE.

Upon entering the maze, turn to the right; afterwards, whenever there is a choice between the left and right, turn to the left, and the centre will soon be reached. Reverse the process in coming out.