Hyp'someter - 1. instrument for measuring altitudes by determining
the boiling point of water at a given altitude. 2. any instrument
used to calculate the height of trees. [hypso - from Greek, indicating
height; also cf. hypsometry, in mapping; hypsography, in scientific
study of earth's topography above sea level.] {Ref. Collins English
Dictionary}
In preparation for the Science Olympics' Metric Madness event,
you can make and test a hypsometer to simplify the to-be-assigned
task of measuring the height of a building. The following gives
instructions based on "The Honour Roll of Ontario Trees, 1990",
published by the Ontario Forestry Association.
Cut out a piece of heavy cardboard, 27.5 cm x 30.0 cm and draw
in the scales as illustrated in Figure 1. Affix 40 cm of thread
through a hole positioned 5 cm from the right hand margin and 2.5
cm from the top] (point A), and weight it with a small nail.
Referring to Figure 2, position yourself 50 metres horizontal distance
from the base of the tree so that you can see the top and base of
the trunk. Holding the hypsometer against your face, with the sight
line at your eye, look along the sight line to the top of the tree.
With your forefinger and thumb press the thread to hold it in place
and read the height from the scale. If you are working with a partner
they can take the readings directly. In the illustration, the reading
is 30 m on the scale when positioned 50 m from the tree. Add the
distance of your eye from the ground to get the height of the tree.
This assumes that you are at the same level as the base of the tree.
Make and practice using this tool before you come to the Science
Olympics. Use it to measure the height of some objects whose height
can be measured with a tape measure, and use this to calibrate your
instrument as accurately as you can. You may be able to think of
some improvements. |