--- title: Rivers, canals and boats: locks, weirs, water-mills, barges and how not to tip a rowing boat — a lesson of Mova's school · trees and pragmatics description: «Rivers, canals and boats: locks, weirs, water-mills, barges and how not to tip a rowing boat», a lesson of the technology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: All of these are real machines and real places that people built and used. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/) / Rivers, canals and boats: locks, weirs… # Rivers, canals and boats: locks, weirs, water-mills, barges and how not to tip a rowing boat Lesson 41 of the technology course of Mova's primary school: 19 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/). - [1](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/1/) — All of these are real machines and real places that people built and used. - [2](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/2/) — A canal is a river made by people. - [3](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/3/) — About 250 years ago Britain dug thousands of kilometres of canals, because a single horse walking on the towpath could pull a boat carrying far more coal than it could pull in a cart on a bumpy road. - [4](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/4/) — Canals cannot run uphill, so engineers built locks: boxes of water with gates at each end that lift a boat up or let it down like a water lift, with no pump at all, only water flowing downhill. - [5](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/5/) — Rivers were tamed too: weirs keep the water deep enough for boats and drive water-mills, but the churning water below a weir is one of the most dangerous places to swim. - [6](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/6/) — So the river bank in the book is full of engineering, if you know where to look. - [7](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/7/) — A canal is a waterway dug by people; Britain's canal age ran from about 1760 to the 1830s, starting with the Bridgewater Canal of 1761, which carried coal to Manchester and made it much cheaper. - [8](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/8/) — A horse that could pull about 2 tonnes in a cart on a road could pull a canal boat carrying about 30 tonnes, because water holds the boat up and there are no bumps. - [9](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/9/) — The horse walked along the towpath beside the canal, pulling the boat by a long rope, while someone on the boat steered with the tiller, a long handle at the back, just like the barge-woman in the book. - [10](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/10/) — Narrowboats are only about 2 metres wide, to fit the narrow locks, and up to about 21 metres long; many boat families lived in a tiny cabin at the back, painted with roses and castles. - [11](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/11/) — To take a boat up through a lock: it goes in, the bottom gates are shut, small sluices in the top gates let water in, the boat rises, and when the water is level the top gates open; the water that flows in is the lock's length times its width times how far the water rises, in cubic metres. - [12](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/12/) — A lock needs no pump: water simply flows down from the higher part of the canal, and reservoirs keep the top of the canal full. - [13](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/13/) — From the 1840s railways took most of the canals' trade, and today about 2,000 miles of canals and rivers in England and Wales are used mostly for holidays, walking and fishing, with a speed limit of 4 miles an hour on canals. - [14](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/14/) — A weir is a low wall across a river that keeps the water deep upstream for boats and can send water to a mill; below it the water churns round and round and can hold a swimmer under, so never swim near a weir. - [15](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/15/) — A water-mill uses moving water to turn a wheel, which turns heavy millstones that grind grain into flour; the Domesday Book of 1086 counted more than 5,000 mills in England. - [16](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/16/) — Sculling means one person rows with two oars called sculls, as the Rat does; in rowing each person holds one oar with both hands; both face backwards, because pulling the oars towards you is the strongest way to row, while a canoeist with a paddle faces forwards. - [17](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/17/) — A punt is a flat-bottomed boat pushed along with a long pole on shallow rivers; a painter is the rope at the front of a boat used to tie it up. - [18](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/18/) — Small boats tip over easily if someone stands up or lunges to one side, as the Mole did when he grabbed the sculls; you step into the middle, keep low, sit still and wear a life jacket. - [19](https://md.mova.elamur.ai/free/en/corpora/school/technology/41-rivers-canals-and-boats-locks-weirs-water-mills-barges-and-how-not-to-tip-a-rowing-boat/19/) — Fast boats make waves called wash that wear away river banks, which is one reason for the canal speed limit and why the Rat shouted at the steam-launches. - ← previous: [Self-driving cars and machines that run themselves](https://md.mova.elamur.ai/free/en/corpora/school/technology/40-self-driving-cars-and-machines-that-run-themselves/) - next →: [Olympiad: machines at home and in the factory ★★★](https://md.mova.elamur.ai/free/en/corpora/school/technology/42-olympiad-machines-at-home-and-in-the-factory/) - ↑ back to [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/)