Most mound ceremonial centers are built near rivers and lakes. Mound builders lived in small communities of families led by elders. They made pilgrimages to the closest ceremonial centers to make offerings to their gods and to bury their loved ones. The ceremonial centers were built on timbers, often with a temple for sacrifices on top and crypts to bury the dead underneath.
There are many different factors that may determine welding sequence. Of course, a 1G weld is defined as a Flat (1) Groove (G) weld and the 1G is usually used when describing the position of welding any flat material such as bar, sheet, or plate. The thickness of the material may affect sequence.
The 3G welding certification qualifies a welder to weld flat, horizontal, and vertical or 1G, 2G, and 3G positions, also includes the 1F, 2F, and 3F positions without having to take the 1G and 2G certification. This one test qualifies you for three positions. These are the positions most commonly used in welding shops.