You can measure any height, if one applies the tenets of Thai. Everything, what you need, is a simple measuring instrument, that can be easily made from cardboard and a piece of wood. You cut a piece of cardboard like this, that it 10 cm wide and 11 cm long. On the lower edge, started from the right, you apply the measure in centimeters. If you want more accurate results, divide the spaces between the centimeter lines into tenths, also in Millimeter. Then the tick marks are numbered. Now take a narrow piece of wood, about 1 cm thick and 10 cm long, and knocks two small nails into the wood, as the drawing shows. Then the wood is attached to the cardboard with glue or thumbtacks
Now you take one 15 cm long cord and attaches a nail or the plumb line of a fishing rod to one end. The other end is attached to the right corner of the cardboard just below the wood. Now you have a measuring instrument. To measure the height of an object, you align the cardboard diagonally upwards.
The aim is to use the two nail heads to aim for the highest point of the object. The plumb line now hangs down across the scale. We write down the number, which shows the plumb bob on the scale. Then the distance to the object is measured in meters, multiply this distance by the number of centimeters on the scale and calculate the result 10 divided. Then the height of the measuring instrument above the ground is added, and you have the result.
For example, if the string is hanging down on the cardboard at the number 3, and one is 40 Meters from the tree, one multiplies 3 · 40 = 120, then one divides through 10, that makes 12. Is the measuring instrument 1 Meters above the ground, is the tree 13 m high.
With this simple measuring instrument one can, like the surveyor with the theodolite, measure the height of each object.