1/13/2024 0 Comments Plumb bob drawingChalk boxes are only suitable for vertical lines. For plumb lines on ceilings, the chalk box is the best device. Plumb bob and chalk box require a bit of practice and patience in the beginning. Which one of theses three measuring devices is favoured is purely down to individual preferences. The chalk line/chalk box is a more modern variation of the theme. The plumb bob is one of the oldest ways of creating a dead straight line (also known as "plumbing"). The spirit level is the classic amongst those tools it is easy to use and almost every household has one. Of course, now the same level of accuracy is achieved by many different sensors and electronic tools.Three tools with the same purpose: to create a straight line for the first length of wallpaper or the one after an internal corner, respectively. Plumb bobs were used in construction as well as regular inspections of skyscrapers. And that’s why plumb bobs were prefered over more modern tools – a plumb bob never lies. Precision in construction, therefore, is critical. Obviously, this can lead to elevators getting stuck or being generally unreliable. Minor errors in construction, as well as strong winds and earthquakes, can cause elevator shafts to bend or twist. And in some cases it was a matter of safety.Įlevator shafts must be straight and smooth. They were also used in the construction of early skyscrapers, even when spirit levels and other tools were already available. Plumb bobs were used to build cathedrals, castles and bridges. Heavy plumb bobs stopped swinging quicker and were more immune to winds, which is why they were commonly used in construction of extremely tall objects. The heaviest plumb bobs were used in the construction of bridges and aqueducts and weighed around 90-100 kg. ( Bybbisch94, Christian Gebhardt, Wikimedia(CC BY-SA 4.0) Sculpture of a construction worker using a plumb bob. One leg of a square needs to be indexed against the plumb line, which automatically puts the other leg parallel to the ground. In this case a plumb bob would be paired with a square. They were often used to ensure that the floor of the building is level or that the pavement of the yard has a sufficient grade to rid itself of rainwater. However, plumb bobs were also used to create straight horizontal lines and level surfaces. Not just for measuring perpendicularityīecause plumb bobs use gravity and were commonly used in the construction of walls, towers and churches, it may seem that it is only good for measuring perpendicularity. There are several huge collections of antique plumb bobs in the world. Plumb bobs do not age, unless they are broken. It’s funny, but true – these museum pieces would still work just fine today. The metal construction allowed thousands of ancient plumb bobs to survive to this day. Pointy end was critical for the accuracy of measurements and hard metals retain their shape better. This gives the plumb bob the necessary weight, but at the same time keeps its surface hard. However, lead is a relatively soft metal, so antique plumb bobs are often bronze or brass with a lead core. ( Gaius Cornelius, Wikimedia(CC BY-SA 4.0) A heavy lead plumb bob stops swinging quicker, although in some cases plumb bobs were filled with a liquid – mercury, water or even molasses – to dampen the movement.Īn ancient Roman plumb bob. Plumb bobs had to be made from a heavy metal so that wind would move the plumb line too much. The name “plumb bob” refers to the material that this tool was made of in the past – the Latin plumbum means lead. Plumb bobs are used not only by builders, interior decorators, electricians, construction engineers and carpenters, but also by well diggers, foresters, astronomers, shipbuilders, artillerymen, mining engineers, scale makers and calibrators, pipeline layers, road builders, etc. The plumb bob is one of the few tools that is (or was) used by people from so many different professions. As a result, plumb bobs were often ornamented, characterised by a beautiful curved shape, and were depicted in art and heraldry. For example, the book of Isaiah says, “I will make justice the measuring line and righteousness the plumb line.” Whether you are a believer or not, this shows the symbolism of the never-failing plumb line in Western culture. ( Andreas Praefcke, Wikimedia(CC BY 3.0)īecause of this objective and eternal accuracy, the plumb bob is mentioned several times in the Bible.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |