Without photography the discovery of X-rays and radio-activity might well have been postponed for decades, and even then remained but a sclentiü. curiosity. Only through photography was the investigation and application of X-rays possible, and today throughout the world the value of X-rays in the diagnosis and treatment of disease and injury is far beyond computation. It has led to the development of entirely new fields in surgery, it has revolutionised the treatment of numerous diseases and has given the medical profession a knowledge of the anatomy of the living ssu ject which was entirely lacking only forty years ago.
Modern Spectroscopy is photography, and from being the'preserve of the astronomer and the rarely used accessory in the chemical laboratory it bids fair to revolutionize our ideas and methods of chemical analysis. It is rapidly becoming an indispensable method of accurate and speedy analysis. In metal-surgical work and factories where only a year or two ago analyses of metals and alloys used in many industries required from two to three days to complete, they are now made spectroscopically in half an hour. In a great foundry where thousands of tons Of molten iron are cast weekly, chemical analysis has been entirely superseded and an analysis of the actual melt is made in seven minutes with an accuracy and a completeness that no other method can approach and at a cost of a few pence.
Photomicrography has made possible the resolution and investigation of structures far beyond the limit of human vision, and in conjunction with X-ray crystal analysis hi made a new science of metallography, so that in place of the old empirical methods of preparing alloys we can today produce materials of exact specification both as to Chemical composition and physical properties having resistance to high temperatures and stresses that but a few years ago were beyond the wildest dreams of the engineer Cinematography Let us take another field, cinematography, who shall assess its value today? As an educational medium its*possibilities are only it. process of recognition, as entertainment it has laid the world in its debt, but it has yet other claims to our gratitude. By its aid some of the most difficult problems in disease are being unravelled, we can watch the action of bacteria on the blood and tissues, we can examine the marvellous process of cell division, we can compare the effect of malignant disease in different tissues and follow the effect of treatment. In other sphere we can study the genesis and propagation of explosion waves, watch minutely the behaviour of high speed machinery and from our observations design better, faster, and safer units. In all this it is photography that has rendered possible such amazing progress. We all hail photography as a delightful hobby and pastime, it is that and something very much more. It is a great servant of humanity without which Progress, as we know it today, would be utterly impossible
Text read from the printed page and cleaned; old type leaves the occasional error.