SCHOOL ESSAY.

Manawatu Herald, Volume XXXVII, Issue 1442, 31 August 1915, Page 3

SCHOOL ESSAY.

The following is the first prize essay on Mr Boynton’s lecture on “Eight,” delivered last month at the local State school. The winner is Florrie Chalk, St. VI., aged 13 years and 6 mouths : “On Friday, Mr Poynton delivered a delightful lecture on that most wonderful subject of science, light. The children of the senior standards attended it, and received a knowledge of some things which are taught only at the universities. A subject similar to light is sound, but light is much more wonderful. Bight travels much the quicker, going round the earth about seven times, while sound merely goes r,060 feet, in a second. The number of vibrations of a high note is a great deal more than that of a low note, the high note having 6,000 vibrations and the low 400 vibrations. This has been tested and proved by scientists. The rate at which light travels has been measured by the following device; A mirror was placed on one hill, and another, so as the light from it would be reflected on the other mirror, on the second hill. The time the light took to go from one to the other was then measured. Light is brought to us by disturbances in the ether, a subject 100 deep lor us yet to understand. This ether extends right to the remotest star. When the light reaches ns it is in the form of a white light. It strikes the flowers, and some absorb all the colours excepting red, which they throw out. These appear to us to be red flowers. It is the same with other flowers, only they throw out different colours. The colours light consists of are red, orange, yellow, green, blue, indigo and violet. The longest rays are the red, of which 30,000 go 10 an inch ; the shortest rays are of a violet hue, and it takes 60,000 of them to make an inch. Green rays are in the centre of these, and 50,000 of them fill the space of an inch. At the lecture we were shown how when we see our reflection the left is where the right should be. An example of this is, when one throws a hall at a wail it will bounce back at an angle according to the one at which it is thrown. If it is thrown at right angles it will bounce back to the thrower, hut if it is thrown side ways it will glance off. We were shown also how an object Is magnified. A piece of glass thicker in the centre than around the circumference will draw the bent rays to one point. The eye placed at the termination of the rays can see the object in front of the glass many times larger than the original size. I was glad to find out how the rainbow, or “God’s arch of promise,” was formed. This can only take place when the snn is shining and the rain falling. When light shines on any clear prisms or globules lire seven colours can he seen. Tire sun, therefore, shines on the globules ot rain, and the colours show. The red rays, being longest, are not bent so much as the blue, therefore they appear higher. This goes on until the entire arch is formed. Newton first found that when two watch glasses are placed face to face the colours can he seen in the form of rings.”