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If you've watched an old western you know what a classical mine looks like with it's posts and beams spaced regularly throughout the length of the mine tunnel. The posts and beams carried the load from the ceiling of the mine tunnel to the floor of the mine replacing the rock and ore that had been removed and, hopefully, kept the ceiling from collapsing.
Most minerals are contained in a shallow band so a tunnel six or seven feet high will excavate most of the mineral. Some mineral deposits, notably the Comstock Lode of Nevada, are an exception as the ore deposits may be in bands more than thirty feet deep. What to do?
Philip Deidesheimer, a German mining engineer, was hired in 1860 by the Ophir mine on the Comstock Lode to come up with a solution. He envisioned a honeycomb and designed a lattice work of cubes six feet square stacked upwards as ore was removed. The stacked square cubes allowed ceiling bracing to be carried upward to any height and the six foot cubes allowed a man to work the walls to remove the ore.
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What are the angles of set square?
30 60 set squares 45 set square
where was the magic square invented?
The set square was invented in America in 1860.
Who invented set square?
Philipp Deidesheimer invented the set square in 1860 in America.
What is the usual shape of a set square?
triangle
What are the angles of a set square?
90 degrees
What has the author William H Storms written?
William H. Storms has written: 'Methods of mine-timbering' -- subject(s): Mine timbering
What is timbering in trenches?
When the depth of trench is large or when the sub - soil is loose, the sides of the trench may cave in. The problem can be solved by adopting a suitable method of timbering.
What are the angles of set square?
30 60 set squares 45 set square
Where was set square invented?
The set square was invented in America in 1860.
where was the magic square invented?
The set square was invented in America in 1860.
Who invented set square?
Philipp Deidesheimer invented the set square in 1860 in America.
Why is a set square called a set square even though it is a triangle?
A set square is known as a set square and not triangle because when you divide 180 by 4, then you get 45. Now, if you construct a square with side: 45 degrees and then divide it in half, then you get the measurement 45-45-90.
Which subset does the square root of 13 belong in?
It belongs to many many subsets including: {sqrt(13)}, The set of square roots of integers The set of square roots of primes The set of square roots of numbers between 12 and 27 {3, -9, sqrt(13)} The set of irrational numbers The set of real numbers
Who invented the set square?
Philipp Deidesheimer invented the square set in 1860. He got the idea from a honeycomb's structure.
Notes on Uses of a set square in geometry?
A set square is used in geometry to draw parallel lines. It is also used to make sure that angles are drawn correctly. There are grooves in the set square where a pencil can be inserted to draw a line. There is also a hinge that allows for moving the two pieces of the set square to the proper angle before drawing.
Is the set 0 1 closed under extraction of square root?
No. The square roots of 0.25 are 0.5 AND -0.5, the second of which does not belong to the set.
What is the area of Široka Set?
The area of Široka Set is 1,370,000.0 square meters.
