Its principal tributary is the Sieve, which joins it at Pontassieve, bringing down the waters of the Val di Mugello.
Besides these five books, Fordun wrote part of another book, and collected materials for bringing down the history to a later period.
The others followed at intervals - the fifth, which appeared in 1842, bringing down the narrative to the pontificate of Boniface Viii.
Another kind of application of machinery to coal mining is that of Messrs Bidder & Jones, which is intended to replace the use of blasting for bringing down the coal.
This apparatus has been used at Harecastle in North Staffordshire, and found to work well, but with the disadvantage of bringing down the coal in unmanageably large masses.
