10. _The Maran_, or _Mimram_, rises in the parish of King's Walden, skirts Whitwell on the N., running parallel with the village street, and passing through Welwyn and near Tewin enters the Lea at Hertingfordbury. 11. _The Purwell_, or _Pirall_, rises in the parish of Ippollits and passing W. of Great Wymondley runs to Purwell Mill, and joins the Hiz at Grove Mill. 12. _The Quin_ rises in the neighbourhood of Wyddial, and passing Quinbury, unites with the Rib at Braughing. 13. _The Rhee_, rising a little E. of Ashwell, has but a few miles to flow before it enters Cambridgeshire. 14. _The Rib_ rises at Corney Bury, flows E. of Buntingford, thence turning W. it flows under the bridge at the _Adam and Eve_, runs to Westmill, Standon and Thundridge, finally uniting with the Lea at Hertford. 15. _The Stort_ enters Hertfordshire from Essex at a point near Cannon Wood Mill, and after passing through Bishop's Stortford forms the extreme E. boundary of the county for some distance before quitting it near Cheshunt. 16. _The Ver_ rises near Flamstead, is crossed by the Dunstable Road, N.W. of Redbourn, then recrossed by it. It then skirts St. Albans on the S. and joins the Colne near Park Street. In addition to the cutting of the _Lea and Stort Navigation_ already mentioned, there are other artificial waterways:-- _The Aylesbury Canal_ (a branch of the Grand Junction Canal) crosses the extreme western neck of the county, from S. of Puttenham to S. of Gubblecote. [Illustration: GRAND JUNCTION CANAL AT TRING _The highest water level in England_] _The Grand Junction Canal_ is largely utilised by barges traversing the W. of Hertfordshire. It is conspicuous at Rickmansworth, Boxmoor, and Berkhampstead; it enters Bedfordshire near Marsworth Reservoir. _The New River_ was constructed by Sir Hugh Myddelton, a London goldsmith, in 1609-13, and is largely fed by springs at Chadwell near Hertford. Its course in Hertfordshire is mostly close to and parallel with that of the Lea. The New River caused the financial ruin of its projector; one of its shares is now worth a large fortune. The whole story of this undertaking is very interesting; but as the New River was cut in order to bring water to London that story belongs to a volume on Middlesex. III. CLIMATE