I needed to measure the height of a nearby tree that was too tall to climb.
The story goes like this. My wife had a sudden fear that if a particular old coniferous tree on a neighbor's property was to blow down in a wind storm, it would crush our house. I had an over-confident hunch that it would not. That the tree would fall short of the house because it appeared to me that the tree's height was less than the horizontal distance from the base of the tree to our house. Five minutes after that I began to doubt the accuracy of my hunch. I needed to put some logic behind it. I needed math.
The result, after five more minutes of frantic scavenging around the house for parts the tool was assembled with hot glue and masking tape, then used immediately.
(We're not going to be crushed!)
In fact there is a comforting 15 foot space between the house and the measured point on the ground where the top of the tree would be, were it to fall directly toward us.
Step 1: Gather Materials
This instructable requires the following things to make.
- a 45 degree Drafting Triangle - (aka Set Square in Canada) (from any art supply)
- a mason's line level (from any builder's supply)
- a laser pointer (from office supply store)
- Hot glue gun
- masking tape
Step 2: Assembly
- Apply a bead of hot glue to the base of the level and centre it on the inside of the triangle.
- Hold the laser pointer along the outside edge of the triangle and secure it with masking tape.