Across
- 4. This article is about the class of double sulfates of aluminium
- 7. It's an underground pipe or tunnel system for transporting sewage from houses and commercial buildings (but not stormwater) to a sewage treatment plant or disposal.
- 9. There were three major types of this bridgewooden, pontoon, and stone
- 10. These are a structure designed to bridge a large vertical distance between lower and higher levels by dividing it into smaller vertical distances.
- 11. It's an instrument used for measuring density or relative density of liquids based on the concept of buoyancy.
- 13. It's a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.
Down
- 1. This was the first portable calculating device for engineers, merchants, and presumably tax collectors.
- 2. It's a system of central heating in a building that produces and circulates hot air below the floor of a room, and may also warm the walls with a series of pipes through which the hot air passes.
- 3. It's an ancient and historic mining method using a flood or torrent of water to reveal mineral veins.
- 5. It's a method of carving an object such as an engraved gem, item of jewellery or vessel.
- 6. It's a farm tool for loosening or turning the soil before sowing seed or planting.
- 8. It's a type of pipe organ blown by air, where the power source pushing the air is derived by water from a natural source (e.g. by a waterfall) or by a manual pump.
- 9. It's farm implement or person that reaps (cuts and often also gathers) crops at harvest when they are ripe
- 10. It's a heat engine that performs mechanical work using steam as its working fluid.
- 12. It's an architectural element similar to the hollow upper half of a sphere.