Wednesday, August 09, 2006
A hose and a string
Hello,
Turning simple things into great instruments
He carries a hose and a string in a dirty battered pail. He moves as he works. He makes sure that the line is straight or the floor slopes at the right gradient. He bends and squats, checks and adjusts, and finally he is satisfied that all measurements are in place. And all the while the instruments he uses are just a length of transparent narrow plastic fish tank hose and a coil of string.
Who or what is he ? Is he a carpenter, a mason or a tiler ? He is really any one of these three workmen. Such cheap and simple things in their hands become great instruments, amazingly remarkable and admirably laudable.
I have always wondered how workmen can raise buildings vertically upright into the sky, how walls are raised vertically and floors are made horizontally flat, how rafters are nailed at the same distances apart and cut to the same level edge, and how tiles are laid to the exact pattern with all the cuts and fits.
Or in specific terms, how does one build a brick pillar four metres high vertically, draw a straight line ten metres long, or make one end of the toilet floor two inches higher than another around a corner out of sight, or lay the tiles in parallel in both directions from wall to wall thirty metres apart ? One can be sure that these things would be of as much use as expensive and sophisticated instruments like theodolites and spirit levels under the same situations.
So, how do these workmen employed these fine instruments ?
When the hose is filled with water, this water will rise to the same level at both its ends. These two ends can be taken to any two different places, and any relative difference in height can be marked accordingly. When a string is plumbed from a height to a lower level, this string is the vertical line between these two points, seen from any direction. This string can be nailed and fixed in place as desired. When a string is coated with ink and held at both its ends on the intended line and plucked at some point and let go, this string will imprint the straight lie required.
Are these not ingenious know-how ?
Simple people use simple equipment but do great work !
Have a nice day
Ronald
Turning simple things into great instruments
He carries a hose and a string in a dirty battered pail. He moves as he works. He makes sure that the line is straight or the floor slopes at the right gradient. He bends and squats, checks and adjusts, and finally he is satisfied that all measurements are in place. And all the while the instruments he uses are just a length of transparent narrow plastic fish tank hose and a coil of string.
Who or what is he ? Is he a carpenter, a mason or a tiler ? He is really any one of these three workmen. Such cheap and simple things in their hands become great instruments, amazingly remarkable and admirably laudable.
I have always wondered how workmen can raise buildings vertically upright into the sky, how walls are raised vertically and floors are made horizontally flat, how rafters are nailed at the same distances apart and cut to the same level edge, and how tiles are laid to the exact pattern with all the cuts and fits.
Or in specific terms, how does one build a brick pillar four metres high vertically, draw a straight line ten metres long, or make one end of the toilet floor two inches higher than another around a corner out of sight, or lay the tiles in parallel in both directions from wall to wall thirty metres apart ? One can be sure that these things would be of as much use as expensive and sophisticated instruments like theodolites and spirit levels under the same situations.
So, how do these workmen employed these fine instruments ?
When the hose is filled with water, this water will rise to the same level at both its ends. These two ends can be taken to any two different places, and any relative difference in height can be marked accordingly. When a string is plumbed from a height to a lower level, this string is the vertical line between these two points, seen from any direction. This string can be nailed and fixed in place as desired. When a string is coated with ink and held at both its ends on the intended line and plucked at some point and let go, this string will imprint the straight lie required.
Are these not ingenious know-how ?
Simple people use simple equipment but do great work !
Have a nice day
Ronald
# posted by chunmu @ 7:55 PM 
