1 calorie of heat is the amount needed to raise 1 gram of water 1 degree Centigrade. 1 calorie (cal) = 4.184 J. (The Calories in food ratings are actually kilocalories.) A BTU (British Thermal Unit) is the amount of heat necessary to raise one pound of water by 1 degree Farenheit (F). 1 British Thermal Unit (BTU) = 1055 J (The Mechanical Equivalent of Heat Relation) 1 BTU = 252 cal = 1.055 kJ.
San Antonio River Walk. A couple strolls along the River Walk. The San Antonio River Walk (also known as Paseo del RÃ­o or simply as the River Walk) is a network of walkways along the banks of the San Antonio River, one story beneath the streets of San Antonio, Texas, USA.
The upper river flows through Texas State University and San Marcos and is a popular recreational area. It is joined by the Blanco River after four miles, passes through Luling and near Gonzales, and flows into the Guadalupe River after 75 miles (121 km). This course is the first leg of the Texas Water Safari.