burthen

kuormata

taakka, kuorma puhekieltä The tonnage of a ship based on the number of tuns of wine that it could carry in its holds.
(archaic spelling of)
1798, w:William Wordsworth|William Wordsworth, s:Lines composed a few miles above Tintern Abbey|Lines composed a few miles above Tintern Abbey, lines 36-43:

Nor less, I trust,

To them I may have owed another gift,

Of aspect more sublime; that blessed mood,

In which the burthen of the mystery,

In which the heavy and the weary weight

Of all this unintelligible world,

Is lightened:

It was with a daughter of Mr Shepherd, who had returned, after an unprosperous marriage, to her father's house, with the additional burthen of two children.

Bidding them grope their way out and bestir,

(...) though the worst

Burthen of heat was theirs and the dry thirst

The other men were variously burthened; some carrying picks and shovels - for that had been the very first necessary they brought ashore from the Hispaniola - others laden with pork, bread, and brandy for the midday meal.