Jan. 21.] THE NEW ZEALAND GAZETTE. 301

Make or procure a simple pulley; mount it and pass a silk cord over it. Attach equal weights to each end. Substitute the rubber cord fixed as above for one weight. Hang the other weight to it. How much is the rubber stretched? Replace the silk cord on the pulley; note the result. Incline the board at different angles. What pull is exerted by the cord over the pulley? Repeat the experiment with the inclined plane; but, instead of attaching the wagon to the rubber cord, attach the power by a silk cord passing over a pulley fixed at the higher end of the plane. Find the ratios weight/power, and length/height as before.
Vary the inclination of the plane, and so get law of inclined plane.
At this stage pupils may be able to express their ideas of mass, weight, and force more or less clearly.
Repeat the last experiments. Detach the wagon from the silk cord, and keep it in position with the finger: with what force does it press against the finger? Remove the finger: what happens? What force drives it down the plane?
Take or make a large glass syringe with a wooden piston with cotton-wool or woollen-yarn packing. Take out the piston, and put a small glass marble or bulb inside the nozzle of the syringe. Make a small hole in the piston, and fit the top with a small valve of rubber sheeting.
Illustrate principle of common pump. The apparatus may easily be converted into a model of the common pump.
Place an iron rod with its ends on two bricks (or wooden blocks); drive a nail into one brick to prevent the rod from slipping. On the other brick place a piece of steel wire or a darning-needle at right angles to the rod, so that the end of the rod rests upon the wire, which is free to turn round. At one end of the wire, at right angles to it, attach a thin piece of straw or a fine splinter of wood. Find how many revolutions the straw makes when the rod is pushed on one inch. (Use a protractor to measure the angle or fraction of a revolution.) Set light to some methylated spirit in a narrow tin dish placed under the rod, and note the greatest expansion that takes place.
Repeat the experiment with a brass or copper rod, using the same amount of spirit.
Take an ordinary screw-wrench or spanner and a brass curtain-ring or a penny. Adjust the screw so that the ring or penny will just pass between the jaws of the wrench. Heat the ring or penny, and then try to make it pass through the jaws.
Fit a flask with a stopper and glass tube, and fill it with water (with which may be mixed a little ink or a solution of indigo). Heat the flask, and note the result.
Let the flask cool. Pour out half the water, but let the lower end of the glass tube be below the surface of the water. Heat the flask again, and note the result. Why does the water in the tube rise higher than before?
Let the flask cool. Pour out all the water, and fit the stopper with a narrow tube bent at right angles. Attach the open end of the bent tube by rubber to the open U tube used before. In the U tube place some water or mercury. Heat the flask, and note the result.
Repeat the last three experiments, putting a thermometer into the flask. Note the readings of the thermometer.
What is the temperature of the air in the room? of the water from the tap? of the air outside? in the sun? What temperature is shown when the thermometer is held inside your mouth?
Find the temperature of the steam immediately above the surface of boiling water.
Find the temperature of melting ice.
Put some pieces of ice into water. Why does it float?
Into the jar used for measuring volumes put some water cooled, say, to about 40° Fahr. and a piece of ice, as large as possible, enclosed in enough wire netting or perforated zinc to make it sink. Note the temperature and volume. Watch the change in temperature. Wait until the water is at freezing-point. When the ice has just melted, note the temperature of the water and the volume.
Melt a piece of candle gently in a test-tube; find the temperature when the candle is nearly all melted. When it is completely melted, throw in one or two small pieces of the same candle. Do they float or sink? Why?
To this course may be added experiments to explain conduction, radiation, and convection of heat; ebullition, evaporation, distillation, condensation of vapour; the formation of clouds, rain, and dew; the principles of ventilation.
Daily readings of the thermometer should be taken, and a record kept. Use maximum and minimum thermometer for this purpose if possible.