Boys often exhibit the earliest physical signs of puberty between the ages of 10 and 16. They grow the fastest between the ages of 12 and 15. Boys' development spurts occur around two years later than females'. Most males have finished growing by the age of 16, but their muscles will continue to develop. Males can also grow taller. The average male reaches his maximum height around age 20-21, but it can vary from 17 to as much as 24 years old. Maximum human height has been reported to reach 213 inches (530 cm) and more recently 247 inches (620 cm). The tallest person ever recorded was an American named Benjamin Thompson, who lived in Cincinnati, Ohio. He was measured at 􏰀216⁄8 inches (547 mm) tall in 1838, when he was only 21 years old. The next year another man was recorded as being 􏰀217⁄8 inches (547 mm) tall, so it appears that Thompson grew even taller after his first record measurement. This guy's name was Charles Langdon and he was born in Tennessee. It is possible that both men reached their maximum heights before the invention of the measuring stick, which would make them remarkable individuals indeed! After reaching its maximum height, a bone or bones within the body begin to shrink, indicating that the person is becoming shorter.