Belgian Transit of Venus Observation Site
Historical marker location:The year 1639 marked the first recorded observation of Venus crossing the sun. Sir Edmund Halley (1656-1742) later predicted that using data from such crossings, known as transits, scientists could precisely quantify the astronomical unit of distance and measure the size of the solar system. The transits of Venus predicatably come in pairs, eight years apart, approximately every 120 years. Scientists from around the world traveled to observation sites during the next events, in 1761 and 1769, but timing of the transits was difficult due to the "black drop effect," in which two objects against a bright background appear to blend. For more than a century, astronomers prepared for the next opportunity to record Venus' transit.
Jean-Charles Houzeau (1820-1888) was a Belgian astronomer with an eclectic history. From 1859 to 1861, he worked as a surveyor in Uvalde, Texas. An abolitionist, he left Texas at the start of the Civil War. In the late 1870s, he returned to Belgium, where he became director of the Royal Observatory and planned the Belgian teams that would go to the western hemisphere to observe the December 1882 transit of Venus. He chose one site in Chile and one (22 feet east) in San Antonio. Good observations required clear skies, and San Antonio offered the chance of favorable weather, as well as good logistics for communication and transportation. A U.S. Naval Observatory team observed from a site on the grounds of nearby Fort Sam Houston.
Using a heliometer, a device he had developed for the observation, Houzeau obtained 124 photographic plates of Venus silhouetted against the sun. Because of clearer conditions, the team in Chile obtained 606. The Belgian findings equaled those of larger nations, and Houzeau's decision to bring an international team to San Antonio provided the city recognition as part of astronomical history. (2005)
As one of the most visible programs of the Texas Historical Commission (THC), historical markers commemorate diverse topics in Texas history, including: the history and architecture of houses, commercial and public buildings, religious congregations, and military sites; events that changed the course of local and state history; and individuals who have made lasting contributions to the state, community organizations, and businesses.
In the late 19th century, Texas became known for its cattle drives, in which cowboys would move herds of cattle from Texas to railheads in Kansas and other northern states. The cattle drives were dangerous and difficult work, but they played a key role in the development of the American cattle industry.
During the Texas Revolution in 1836, the Battle of the Alamo took place, where a small group of Texan defenders valiantly fought against Mexican forces. Although the defenders ultimately lost, their bravery and sacrifice galvanized the Texan cause. Soon after, the Republic of Texas was established, and Bexar County was officially created in 1837, named after San Antonio de Béxar.
Bexar County played a vital role in the westward expansion of the United States. It became part of the United States when Texas joined as the 28th state in 1845. The county saw significant growth with the construction of railroads, the establishment of military bases like Fort Sam Houston, and the influx of European immigrants. In 1968, HemisFair '68 brought international attention to the county, showcasing its rich cultural heritage and attracting visitors from around the world. Today, Bexar County is known for its vibrant tourism industry, robust military presence, renowned healthcare institutions, and prestigious educational establishments.
Bexar County Timeline
This timeline provides a condensed summary of the historical journey of Bexar County, Texas.
Pre-19th Century: The region that would become Bexar County was inhabited by various Native American tribes, including the Coahuiltecan and Lipan Apache.
1718: The Spanish established the Mission San Antonio de Valero, known today as the Alamo, in what is now downtown San Antonio. This marked the beginning of Spanish colonization in the area.
1821: Mexico gained independence from Spain, and the region came under Mexican control.
1836: The Battle of the Alamo took place during the Texas Revolution, where a small group of Texan defenders fought against Mexican forces. Though the defenders were ultimately defeated, their resistance became a symbol of Texas independence.
1837: The Republic of Texas officially established Bexar County, naming it after San Antonio de Béxar, the former Spanish name for the area.
1845: Texas joined the United States as the 28th state.
1861-1865: During the American Civil War, Bexar County remained part of the Confederacy.
Late 19th-early 20th century: The county saw growth and development with the expansion of railroads, the establishment of military bases like Fort Sam Houston, and the arrival of European immigrants.
1968: HemisFair '68, a world's fair, was held in San Antonio, bringing national and international attention to the city and the county.