Convert from truss to petagram

Unit Definition (truss)
The truss is a traditional weight unit, generally equal to 4 stone or 56 pounds (about 25.4 kilograms). The truss was used primarily for measuring hay. In 1795, Parliament specified that a truss of hay should equal 56 pounds for old hay or 60 pounds (about 27.2 kilograms) for new hay.

Unit Definition (petagram)
The petagram is a metric unit of mass equal to 10E15 grams or 1 gigatonne (one billion metric tons). This unit is used in atmospheric science and other scientific contexts where large masses are considered.