Samuel Langley

Samuel was a man who loved stars.

He studied the sky. He also built tools to measure heat. One tool helped us learn about the sun.

Samuel also wanted to fly. He made small models that could fly. These models used steam engines. They flew very far across the water.

Next, he built a much larger plane. He called it an Aerodrome. He wanted a person to fly in it. He used a big machine to launch it.

He tried to fly the big plane twice. Both times, the plane crashed into the river. The pilot was safe, but the plane broke.

Samuel's work helped us understand the air and the stars. He was a great explorer of science.

Samuel Pierpont Langley was a scientist who studied the stars and the air.

He worked at the Allegheny Observatory. There, he helped make a new way to tell time. He used stars to create the Allegheny Time System. This system sent exact time to railroads using telegraph lines. This helped trains run safely without crashing.

Langley also invented a tool called a bolometer. A bolometer is a device that measures heat. It was so sensitive it could feel tiny changes in temperature. This tool helped scientists study the sun. It also helped people learn how gases in our air affect heat.

Langley wanted to build a plane for people to fly in. He called his large plane an Aerodrome.

His small models flew well using steam engines. However, his big plane had trouble. He tried to launch the Aerodrome from a boat using a catapult. The plane crashed into the river twice in 1903. The pilot, Charles Manly, was not hurt.

Even though the big plane failed, Langley's work helped science grow.

Samuel Pierpont Langley was a scientist who studied the stars and the air.

He was an astronomer, a physicist, and an aviation pioneer. Langley worked at many places like the Harvard College Observatory and the United States Naval Academy. He later became the director of the Allegheny Observatory in Pittsburgh. He also served as the third Secretary of the Smithsonian Institution. His many discoveries helped us understand the sun and how to fly.

One of his most important jobs was creating a way to tell time. In the 1860s, clocks were wound by hand and were often wrong. This was dangerous for railroads because trains could crash if they used different times. Langley used a small transit telescope to watch stars cross a specific line in the sky. He used these star observations to create the Allegheny Time System. He sent these exact time signals through 4,713 miles of telegraph lines. This helped trains in the US and Canada run much more safely.

Langley also invented a special tool called a bolometer. A bolometer is an instrument used to measure far infrared radiation, which is a type of heat. This tool was incredibly sensitive to temperature. It could detect a change of less than 1/100,000 of a degree Celsius. Langley used it to study the sun and the moon. His data helped a scientist named Svante Arrhenius calculate the greenhouse effect. This helped us learn how gases in our air affect the Earth's heat.

Langley spent many years trying to build a plane for people to fly in. He called his large machines the Aerodrome, which means "air runner." Before building the big plane, he made small models that worked well. In 1896, his steam-powered model Number 5 flew a long distance after a catapult launch. He even used a rotating arm to act like a wind tunnel for his tests. He wanted to find how much power a plane needed to stay in the air.

Building the full-sized Aerodrome was a very hard job. He hired an engineer named Charles Manly to help build a powerful engine. The engine had 50 horsepower, which was much stronger than the Wright brothers' engine. However, the big plane had trouble staying steady in the air. Langley tried to launch it from a boat on the Potomac River using a catapult. The plane crashed into the water twice in 1903. Luckily, the pilot was not hurt during these crashes.

Samuel Pierpont Langley was a versatile American scientist who shaped several fields of study. He worked as an astronomer, a physicist, and an aviation pioneer.

Throughout his career, he held many important roles. He served as the third Secretary of the Smithsonian Institution. He was also a professor of astronomy at the University of Pittsburgh. During his time there, he directed the Allegheny Observatory. His work helped people understand the sun, the stars, and the mechanics of flight.

In 1867, Langley arrived at the Allegheny Observatory in Pittsburgh. At that time, the institution was in a state of disarray. The equipment was broken, the library was missing, and the building needed repairs. With the help of an industrial leader named William Thaw Sr., Langley improved the equipment. He installed a small transit telescope to observe star positions. This telescope tracked stars as they crossed the celestial meridian. These precise observations allowed Langley to develop a new way to manage time.

Before Langley's work, railroad travel was often dangerous due to timing issues. Clocks were wound manually and were frequently imprecise. If a train engineer and a switch operator had different times, collisions could occur. Langley created the Allegheny Time System to solve this problem. He used astronomical observations to provide a precise time standard. He distributed these signals via 4,713 miles of telegraph lines. This service reached railroads across the United States and Canada. The revenue from these time signals helped fund the observatory for many years.

Langley also made significant contributions to the study of heat and light. In 1880, he invented the bolometer. A bolometer is a highly sensitive instrument used to measure far infrared radiation. This radiation is a form of energy often felt as heat. The device could detect temperature changes smaller than 1/100,000 of a degree Celsius.

Using the bolometer, Langley studied solar phenomena and the moon. His data on how carbon dioxide interferes with infrared radiation was vital. It allowed scientist Svante Arrhenius to make the first calculations regarding the greenhouse effect.

Beyond astronomy, Langley was deeply interested in the mechanics of flight. He began experimenting with gliders and rubber-band powered models in 1887. He built a rotating arm to function like a wind tunnel. This allowed him to test how different shapes moved through the air. He discovered that a 1 lb. brass plate could be kept aloft by very little spring tension. In 1896, his unpiloted steam-powered model, Aerodrome No. 5, successfully flew after a catapult launch. This flight was ten times longer than previous experiments with heavier-than-air machines.

Langley eventually attempted to build a machine for human pilots. He called these large aircraft "Aerodromes," a name derived from Greek words meaning "air runner."

He received $50,000 from the War Department and $20,000 from the Smithsonian to fund this work. He hired engineer Charles M. Manly to help design a powerful engine. This engine produced 50 horsepower, which was significantly more than the 12 horsepower used by the Wright brothers. However, the Aerodrome lacked effective roll control. It relied on the dihedral angle of the wings to stay level.

Testing the manned Aerodrome proved to be a difficult and unsuccessful process. Langley chose to test the craft over the Potomac River to avoid landing on solid ground. He used a catapult launched from a boat to get the plane moving.

On October 7, 1903, the first attempt failed when a wing clipped the catapult. The craft plunged into the river like mortar. A second crash occurred on December 8, 1903, when the machine broke apart during launch. Although the crashes were public failures, Manly was unhurt in both instances.

Langley's legacy remains a subject of historical discussion. In 1914, Glenn Curtiss flew a modified Aerodrome to help defend the Smithsonian's reputation. The Smithsonian later displayed the craft as the first man-carrying airplane capable of sustained free flight. This claim led to a long feud with Orville Wright, who disagreed with the Smithsonian's view. Despite the controversy, Langley's work in physics and timekeeping remains fundamental. His inventions and observations provided a bridge to modern aviation and climate science.