A PARENT NIGHT PROGRAM 891

DEMONSTRATION OF HYDROGENBY BOB FILERS

In the bottle on the shelf is dilute hydrochloric acid. When the stop-cock is released, this allows the acid to run down the tube by the siphonprinciple into this bottle »which is called the gas generator. In it are a fewpieces of zinc with which the acid reacts to form the hydrogen. The pres-sure created in the generator forces the hydrogen through the glass tubeinto the pneumatic trough which is filled with water. Hydrogen can becollected by displacing water, because it is practically insoluble. Hydrogenburns in the presence of air, and when it is ignited it burns quietly down thetest tube. This time we shall use only a half tube of hydrogen, and therest, air. Now when it is ignited, a sharp bark is heard. This is the explosioncaused by the mixture of hydrogen and air. When hydrogen burns in thepresence of oxygen, water is formed. This is not noticeable inside the tubebecause the tube got wet when the hydrogen was collected by the displace-ment of water. Hydrogen is not prepared commercially in this manner be-cause it is far too expensive. Water gas is used. This is made by passingsteam over heated carbon. This forms two products, hydrogen and carbonmonoxide. A certain chemical process is used to separate the carbonmonoxide from the hydrogen. Hydrogen, by itself, will not burn, but whenmixed with air is very explosive. It is used in dirigibles, balloons, etc., andin hydrogenation. This is a process by which hydrogen is mixed withcertain waste oils to form usable solids such as lard, crisco, spry, etc.

HOW WE STUDY GENERAL SCIENCEBY FLORENCE RUSSELL

The two main books used in studying General Science are our text-book Everyday Problems in Science written by Charles John Pieper andWilbur Lee Beauchamp and our workbook written by Beauchamp andHarold H. Miller. Our textbook and workbook both are divided intoseventeen units and each unit has a certain number of problems.In addition to our two main books we have many good reference books

pertaining to physics, chemistry and other sciences. These are available tous any time we want them during class, but if we want to take them homeor use them outside of class we have to get permission from our teacher orlibrarian.Every so often the teacher either collects our books or comes around to

each student to correct his workbook. Each exercise that is correct hechecks. As he checks the exercise off we put it on the report, on the bulletinboard, so the other students and teacher may tell how far we have pro-gressed.

THE LAW OF FLOATING BODIESBY JOHN RUSSELL

This set up shows why ships float and why they sink. When a ship goesinto the ocean as it pushes downward it pushes from under it a certainamount of water. We say it displaces a certain amount. What causes thisdisplacement, and how much, is determined by the volume and weight ofthe vessel. The more volume and weight, the more water it pushes away.This "pushed away" water, as we call it, is what holds the ship afloat orwe say it is the buoyant force which floats it. If the ship gets a leak andfills up, the weight of the ship becomes too great for the volume of theship to displace enough water to hold the excess weight up, therefore theship goes down. It goes to the bottom.