Adventures in Electricity #4

# "Exposing the Unknown" A young boy named Johnny injures his arm in an accident and is taken to Dr. Harvey's office, where the doctor uses X-rays to examine the injury. Dr. Harvey explains to Johnny and his family the history and applications of X-rays, beginning with a scientist's accidental discovery of an invisible ray called "X" and progressing through its uses in medicine and industry. The story covers the development of X-ray technology, from early Crookes tubes to modern high-voltage X-ray units, detailing how researchers like Roentgen advanced the field and how Coolidge's sectional tube innovation improved X-ray generation for therapeutic and diagnostic purposes. The narrative concludes by noting that X-ray units worldwide now operate at voltages up to 1,000,000 volts, enabling early cancer diagnosis and treatment that saves lives.