the moon, these changes take nearly nineteen months. When Venus is full she is nearly eight times as far away from the earth as when she is new, so her apparent changes of size and shape are quite apparent. Jupiter. This planet has four moons, which are invisible to the naked eye, but can be seen through an opera-glass. They always appear in a straight line, and change position very rapidly. If they are looked at two nights in succession, this change of position enables the observer to tell them from stars, which they resemble. PLANK, a game played by two to four persons, with 12 cards and 24 counters. Each of the cards bears three squares, arranged as in the figure, and colored red, white, and blue, the order of the colors varying on different cards. Plank-card. The counters are divided into four sets, marked respectively with the letters A, B, C, and D, and in each set there are two red, two blue, and two white counters. The cards are divided equally among the players, and each is given a set of counters. The player at the dealer's left lays down a card face upward, and places a counter on a square of the same color. The player at his left may place a counter on the same card, or lay another card close by its side, placing a counter on the second card, and the other players in turn have the same choice. When the cards and counters have all been played, each may move one of his counters to a vacant space of the same color. He who first gets three of his counters, red, white, and blue, in a row, either lengthwise or across the cards, wins the game. No counter may be placed on a square of a different color. PLANTING, a game played by any number of persons, in which each in order tells what he has planted and what came up. The articles planted may be objects or persons of any kind, but they must come up as plants or trees, having some punning connection with the thing planted. Thus, one player may say: "I planted Shakespeare. and Sweet William came up," another, "I planted a pack of cards, and W(h)istaria came up.” PLATINUM, Experiments with. 1. Heat a bit of platinum wire red-hot in the flame of a Bunsen burner. Turn off the gas, and turn it on again at once. The wire will remain red-hot, though it does not light the gas again. The reason is, that platinum condenses gases on its surface. and the mixed gas and air of the burner being thus condensed, unite and give out enough heat to keep the wire red-hot, though not enough to light the gas again. 2. Cut a star, or any other figure, from a piece of platinum, and suspend it by a platinum wire in a wine-glass by fastening the wire to a nail laid across the top of the glass. Put a little alcohol into the glass, about a quarter of an inch from the object, light it, and when the platinum is red-hot, smother the flame by placing a piece of paper or card-board on the top of the glass. By lifting the cover now and then to let air into the glass, the platinum figure will remain red-hot and throw out a bright light, until all the alcohol is exhausted. The effect is very beautiful in a dark room. POETICAL BUTTERFLY, THE. A game played by any number of persons, one of whom, called the But poker. A similar reflection from the air close to the hot sand of a desert is called Mirage (a French word meaning reflection). terfly, names the others after trees, flowers, birds, or insects. The Butterfly pretends to fly from one to another, asking each for his story, and then commenting on it as he pleases. Each of the players, when thus addressed, must give some quotation, or mention some tale or legend, about the tree, flower, bird, or insect he represents. Thus, the Apple-tree may allude to the story of William Tell, and the Robin to that of Cock Robin, while the Black-heads of willow-wood and flexible bird may quote: "Four and twenty blackbirds POETS, a game played by any POLO, the game of HOCKEY played on horseback or roller skates. In the horseback game, called Equestrian Polo, the players ride on ponies not more than 14 hands inch in height, usually Mexican Mustangs. The sticks, or mallets, are from 49 to 52 inches long, with handles covered with buckskin. The balls are made of light wood. The grounds are about 750 yards long and 500 feet wide, and have at each end two goal-posts, 24 feet apart. At the beginning of the game the of paper the name of some well-leaders toss for goals, and the playknown author, and on another slip ers on each side take position in a quotation from his works. The front of their goal behind a line names are then placed in one pile, drawn about 12 yards from it. The and the quotations in another, and ball is thrown into the centre of the each player draws a slip from each field by the umpire, and the game pile. Each, in order, then reads his begins. Sometimes the game is slips aloud, and declares whether opened by "charging," in which or not the quotation drawn is from case the players stand only a few the writings of the author. If not, feet from the ball, and rush upon it he is required to give a quotation | at the word “play;" but as this is from the writings of the author hard on the horses, it is usually whose name is on his slip, and to omitted, except in the opening game name the author of the quotation on the other slip. If he makes any mistake he must pay a forfeit. Another way of playing the game, which makes it entirely one of chance, is simply to exact a forfeit from those players who draw slips on which the names and quotations do not correspond. This game is called in Germany Dichter Errashen (Guessing Poets). POLISH CHECKERS or DRAUGHTS. See CHECKERS. of a match. The object of the game, as in similar ones, is to strike the ball between the opposing goal-posts, called winning a goal. A match game usually consists of three innings of twenty minutes each, with two minute intervals for rest, and the side making the most goals in the sixty minutes of play wins the game. In case of a tie, the game is continued till one party makes another goal. RULES OF THE GAME. The following are the rules of the Westchester Polo Club: POKER, Experiment with. Heat a poker red hot, and then look along its side at an object ten or twelve feet distant. If the poker is 1. The grounds to be about 750 held correctly, three images of the feet long by 500 feet wide, with a object will be seen close to the sur-ten-inch guard from end to end on face, one of which is upside down. the sides only. These images are caused by reflection 2. The height of the ponies must from the heated air close to the not exceed 14 hands I inch. 3. The balls to be of wood, with no other covering than paint, and about 3 inches in diameter. The mallets to be such as are approved by the Steward. 4. The goal-posts to be 24 feet apart, and light enough to break if collided with. 5. Match games between pairs shall be for periods of 30 minutes, time between goals included, unless otherwise specified. 6. Match games between teams of four shall be three periods of 20 minutes each, actual play, time between goals and delays not counted, with 10 minutes between the periods for rest, unless otherwise specified. stop the game, and the time so lost shall not be counted. When the game is resumed, the ball shall be thrown between the players, who shall be lined up at the point at which the ball stopped. But if the game is stopped on account of a foul, the ball is to be thrown in at the place at which the foul occurred. 15. When the limit of time has expired, the game must continue until the ball goes out of bounds, and such over-time shall not be counted. 16. In case of an equal number of goals having been made at the end of the third period, the game to be continued until one side makes the winning goal. 7. Each team to choose an um- 17. When the ball goes out of pire, and, if necessary, the two um- bounds at the sides, it must be pires to appoint a referee, whose de- thrown in from the place at which it cision shall be final. went out, by the referee, or by an im8. Each team shall have a substi-partial person, between the two sides, tute in readiness to play when a match is on. 9. There shall be a captain for each team, who shall have the direction of positions and plays of his men. 10. No captain shall allow a member of his team to appear in the game otherwise than in the Club uniform. which shall be drawn up in line II. No person-players, umpires, and referee excepted-shall, under any circumstances, be allowed upon the ground during the progress of 18. A player requiring a mallet the game. during the game, must ride to the 12. It is forbidden to touch an ad-end or side line. It must not be versary, his pony, or his mallet, with brought on the field to him. the hand or mallet during play, or to strike the ball when dismounted. 13. The game to begin with a charge, the contestants taking their positions behind the chalk-line, which is to be 30 feet from the goalposts. When the signal to charge has been given by the referee, the first and second players must keep to the left of the ball until it has been touched. 14. In case of an accident to a player or pony, or for any other reasonable cause, the referee may 19. Foul riding is careless and dangerous horsemanship, and lack of consideration for the safety of others. A player in possession of the ball has the right of way, and no one shall cross him unless at such a distance as to avoid all possibility of a collision. 20. The referee may suspend a Polo on Roller Skates, or Rink 2. If any teams of five players in a rink or touching the surface. other large hall. The ball is of rub-player catch or bat the ball with his ber, and the sticks, which are curved hands or arm. 3. If any player at the end, are about five feet (save the goal-tend, who may do so) long and one inch in diameter. The kick the ball with his foot or skate, goals, set ten feet from the ends of though he may stop the ball with the rink, are cages six feet wide, either. 4. If any player strike down three feet deep, and three feet the stick of his opponent, or if any high, and to count as a goal, the player trip or strike another intenball must be struck into the cage tionally with stick, hand, or skate. and remain there. 5. If any player throw his stick in the pathway of a player or at a ball. 6. If a player raise his stick above his hip in striking a ball. But in case the ball is in the air, above the hip, he can raise his stick to stop it. RULES OF THE GAME. 1. To start the game, the ball is placed in the middle of a straight line joining the centres of the goals, and at the whistle of the referee is charged upon by a player on each side, who shall start, without aid, from a point on a line with his goal and 18 inches to the left of it. 2. The side scoring most goals in a half hour's play wins the game. 7. Any act by any player that is manifestly intended as an interference with another may be declared a foul by the referee, upon complaint of the captain of the offended side. 8. Three fouls (other than when the ball leaves the bounds) made by either side during a contest for a goal, shall constitute a goal for the opposite side. 3. To count as a goal, the ball must remain in the cage. It must not be removed thence by any person but the referee. Should any player touch the ball in the cage either with his person or stick, or 9. If the referee decide that a foul anything else that indicates his in- made by the goal-tend prevented a tention to remove the ball, the ref-goal, one shall be adjudged for the eree shall decide a goal for the opposite team. other side. 10. All games shall be played on If a ball go out of bounds, the ref-rink skates with plain boxwood eree shall blow his whistle to call revolving rollers, without the use of game, and place the ball at a point additional appliances to hinder the opposite where it went out, at least free running of such rollers. Any four feet from the rail. In recom- woods, rubber, or any other material mencing play, the players who do so attached in any manner to any must stand in position to knock skate, shoe, or boot, is positively the ball up or down, not across, the prohibited. rink with their backs toward the sides, the ball to be midway between two players. 5. Game shall be called by the referee whenever a foul occurs, or whenever one is claimed, unless the referee is satisfied that no just claim exists. Upon claim of foul, if game is to be renewed, the ball must be placed where the foul occurred. 6. It shall be deemed a foul: 1. If any player stop or strike the ball when any part of his person is II. The ball must not be struck hard, but may only be “nursed” or 'coached.' 12. No person, except the players and referee, shall be allowed on any part of the surface during a game. 13. If the rusher, whose place it is to charge upon the ball to start the game, tries to start before the whistle is blown, or does not start from the designated spot, the referee must warn him once; and if he persists, the referee has the authority to call for a new rusher him. He can now take the Ball to start the game. with him in his moves (called "carrying" it), or he may "throw" it, that is, move the Ball like a man. The thrown Ball can pass over the heads of as many men as necessary, but it can be thrown only in a straight line. A player may take the number on one of his dice as a move, with or without the ball, and the other as a "throw," but he can divide them in no other way. Thus, if he throw six-three, he can move up six squares and throw the Ball three, or vice versa, but he cannot, for instance, move seven squares and throw two. He wins who first plays the Ball, either by throwing or carrying it to one of the squares in the opposite goal. The Ball should usually be carried as far as possible, and then thrown over the heads of the opponent's men. Parlor Polo, a game founded on Polo, played by two persons on a board like that in the illustration. History. Polo has been traced The squares are colored alternately back as far as the 8th century, when white and blue, except those occu- it was played in Persia and called pied by men at the beginning of the Chugdn, the name of the longgame, which are red. Each player handled mallet used in the game. has six pieces or men, like CHECK-There is a story that Darius sent ERS, called Goal Tend, Cover Point, Alexander a ball and Chugán, as an two Rushers, and two Half Backs, whose positions at the opening of the game are shown in the figure. A small figure of a polo player on horseback, called the Ball, is placed in the middle of the board. Each player sits behind his own goal, and each plays in turn, throwing two dice to determine his moves. The colored squares alone are used. Any man may be moved a number of colored squares equal to the sum of the numbers thrown, diagonally in any direction, either in a straight or zig-zag line, provided he does not pass over any other man in so doing, nor retrace his steps in the same move. The Rushers must move first, and the Goal Tend must not leave the goal; but aside from this the men are all alike. When a man moves exactly into the square occupied by the Ball, he is said to "have the Ball," and it is placed on insulting hint that he was more fit to play polo than to go to war. It is undoubtedly the equestrian game called "Tennis" in the Arabian Nights. The Byzantine Greeks played it with a stick somewhat like a LACROSSE stick, having at the end a network of gut strings. The game was played both on foot and on horseback. The foot game (our Hockey) was carried to France under the name of Chicane (probably a corruption of Chugán) and from this we get our word chicanery, meaning trickery, from the tricks employed in the game. Equestrian Polo was introduced into England by some cavalry officers about 1865, and the first game was played near Folkestone. There are now many Polo clubs in Great Britain and several in the United States. The first club in this country was the Westchester, which played on the |