On May 15, 1874, the Gay Head Light was changed from flashing white to "three whites and one red" to differentiate the light from the area's two other principal lights located at Sankaty Head and Montauk Point.
All three lights had Fresnel lenses, however, the Gay Head Light was the only light of the 1st Order.
The addition of the red flash signal required the exterior vertical installation of a red screen from top to bottom along every fourth row of prisms of the rotating Fresnel lens.
The illuminator of the Fresnel was a lamp with five concentric wicks, the largest being five inches in diameter.
The light consumed about two quarts of oil an hour, or about seven and a half gallons on the longest nights.
Due to cost savings, the Gay Head Light was converted from increasingly expensive sperm whale oil to lard oil in 1867.
In 1885, the Light was converted from lard oil to kerosene oil.
Although the Fresnel Lens was invented in Europe in 1822, the U.S. Lighthouse Board did not allow it to be installed in America's lighthouses until the Fresnel underwent a series of tests in Navesink, NJ.
Beginning in the early 1850s, Fresnel Lenses were installed in U.S. Lighthouses, with Gay Head Lighthouse receiving one of the first Fresnel Lenses of First Order in 1856.
Due to the superiority of the Fresnel Lens to any other lighthouse optic available in the 19th century, the U.S. Lighthouse Board converted all U.S. lighthouses to the Fresnel Lens system by 1860.

Relative to the subject of lighthouse illuminants – the evolution of fuels used in America's lights went as follows: wood fires and candles were replaced by whale oil with solid wicks.
Whale oil continued to be used via an improved mechanical delivery system when the parabolic reflector system was introduced around 1810.
Whale oil remained the fuel of choice until coiza oil (pressed from wild cabbages) replaced whale oil in the early 1850s.
However, due to certain challenges, America's farmers lost interest in growing and manufacturing coiza oil.
In the mid-1850s, the U.S. Lighthouse Board switched to lard oil (made from animal fat).
Kerosene started replacing lard oil in the early 1870s – with full conversion to kerosene by the late 1880s.
Electricity started to replace kerosene around the turn of the 20th century, with Gay Head Light being electrified in 1954.

Keeper Crosby L. Crocker served as lighthouse Keeper from 1892–1920.
Crocker and his family were reportedly healthy when they moved into the brick Keeper's house in 1892.
During the first fifteen months, Crocker had four of his children die under mysterious circumstances.
Ten years after the death of his four children, his fifth child, George H. Crocker, died at age fifteen.
On similar note, Edward P. Lowe (Keeper 1891–92), who lived at the light prior to Crocker, died after just one year of service.
The cause of the deaths was attributed to toxic spores from mold and mildew growing on the damp brick walls inside the house.
In 1899 the Lighthouse Board voted that the brick house was "too damp and unsanitary for safe occupation by human beings," and recommended $6,500 for a new house made of wood.
As a result, a spacious gambrel-roofed, double dwelling was constructed in 1902.

In 1920, Charles W. Vanderhoop, Sr.
was appointed as the tenth Principal Lighthouse Keeper.
Keeper Vanderhoop had the distinction of being  the only Aquinnah Wampanoag Indian to officially tend the Lighthouse.
 During Vanderhoop's service, the Gay Head Light was well maintained and operated.
This was due in large part to the fact that Keeper Charles Vanderhoop acquired valuable working knowledge of the Fresnel lens apparatus when he served as assistant Keeper at Sankaty Head Light.
Keeper Charles Vanderhoop was renowned for his story-telling abilities – which entertained visitors touring the Gay Head Lighthouse.
According to Charles W. Vanderhoop, Jr., when his father gave former President Calvin Coolidge and his friends a tour of the lighthouse – Coolidge nodded his head or smiled from time to time as his friends talked and asked questions.
At the
On May 15, 1874, the Gay Head Light was changed from flashing white to "three whites and one red" to differentiate the light from the area's two other principal lights located at Sankaty Head and Montauk Point. All three lights had Fresnel lenses, however, the Gay Head Light was the only light of the 1st Order. The addition of the red flash signal required the exterior vertical installation of a red screen from top to bottom along every fourth row of prisms of the rotating Fresnel lens. The illuminator of the Fresnel was a lamp with five concentric wicks, the largest being five inches in diameter. The light consumed about two quarts of oil an hour, or about seven and a half gallons on the longest nights. Due to cost savings, the Gay Head Light was converted from increasingly expensive sperm whale oil to lard oil in 1867. In 1885, the Light was converted from lard oil to kerosene oil. Although the Fresnel Lens was invented in Europe in 1822, the U.S. Lighthouse Board did not allow it to be installed in America's lighthouses until the Fresnel underwent a series of tests in Navesink, NJ. Beginning in the early 1850s, Fresnel Lenses were installed in U.S. Lighthouses, with Gay Head Lighthouse receiving one of the first Fresnel Lenses of First Order in 1856. Due to the superiority of the Fresnel Lens to any other lighthouse optic available in the 19th century, the U.S. Lighthouse Board converted all U.S. lighthouses to the Fresnel Lens system by 1860.
Relative to the subject of lighthouse illuminants – the evolution of fuels used in America's lights went as follows: wood fires and candles were replaced by whale oil with solid wicks. Whale oil continued to be used via an improved mechanical delivery system when the parabolic reflector system was introduced around 1810. Whale oil remained the fuel of choice until coiza oil (pressed from wild cabbages) replaced whale oil in the early 1850s. However, due to certain challenges, America's farmers lost interest in growing and manufacturing coiza oil. In the mid-1850s, the U.S. Lighthouse Board switched to lard oil (made from animal fat). Kerosene started replacing lard oil in the early 1870s – with full conversion to kerosene by the late 1880s. Electricity started to replace kerosene around the turn of the 20th century, with Gay Head Light being electrified in 1954.
Keeper Crosby L. Crocker served as lighthouse Keeper from 1892–1920. Crocker and his family were reportedly healthy when they moved into the brick Keeper's house in 1892. During the first fifteen months, Crocker had four of his children die under mysterious circumstances. Ten years after the death of his four children, his fifth child, George H. Crocker, died at age fifteen. On similar note, Edward P. Lowe (Keeper 1891–92), who lived at the light prior to Crocker, died after just one year of service. The cause of the deaths was attributed to toxic spores from mold and mildew growing on the damp brick walls inside the house. In 1899 the Lighthouse Board voted that the brick house was "too damp and unsanitary for safe occupation by human beings," and recommended $6,500 for a new house made of wood. As a result, a spacious gambrel-roofed, double dwelling was constructed in 1902. 
In 1920, Charles W. Vanderhoop, Sr. was appointed as the tenth Principal Lighthouse Keeper. Keeper Vanderhoop had the distinction of being  the only Aquinnah Wampanoag Indian to officially tend the Lighthouse.  During Vanderhoop's service, the Gay Head Light was well maintained and operated. This was due in large part to the fact that Keeper Charles Vanderhoop acquired valuable working knowledge of the Fresnel lens apparatus when he served as assistant Keeper at Sankaty Head Light. Keeper Charles Vanderhoop was renowned for his story-telling abilities – which entertained visitors touring the Gay Head Lighthouse. According to Charles W. Vanderhoop, Jr., when his father gave former President Calvin Coolidge and his friends a tour of the lighthouse – Coolidge nodded his head or smiled from time to time as his friends talked and asked questions. At the
Gay Head Light