Fourcault process the pit must be "heated back" and then the process can continue anew. Glass chemistry has a huge impact on the process since it controls the melting, forming and annealing temperatures, liquidus temperature (point where various chemicals that make up the glass start to crystallize out of the glass) and rates of change of characteristics of the glass itself. Occasionally the ribbon will break or crack, leading to failure of the drawing process. Such breaks, known as "checks" can be alleviated by using proper operating parameters. Sometimes an expedient measure, using a portable source of heat, can be used to
Heated glass 350 degrees Fahrenheit (177 degrees Celsius). The standard desirable temperature range in buildings is between 104 and 113 degrees Fahrenheit (40 to 44 degrees Celsius). For industrial purposes higher temperatures may be warranted. The first heated glass was created in 1931 by Protes Glass Company, offered for cars. Their product was not a success. Heated glass was first used on a wide scale in World War II to prevent aircraft windshields from frosting over in cold weather and high altitudes. It is still used in aviation for this purpose. Heated glass has been used in architectural applications for the past