1. Navigational Instruments
Measuring the Sky

2. Devices for Measuring Altitude
A Quadrant is a simple instrument for measuring Altitude.
It uses a plumb line and a protractor-like scale
(You made one!)
Disadvantages:
Hard to use on a ship
Not good for the Sun

3. An Astrolabe is also device for measuring altitude.
Its advantage is that it can measure the Sun’s Altitude without looking at it
Disadvantage:
Hard to use on a ship

4. A cross staff is a medieval device for measuring altitude on shipboard
Advantages:
Good on a swaying ship
Can be used to measure angles other than with the horizon
Disadvantages:
Doesn’t Measure small angles well
More Human Error

5. The Kamal was used in the Red and Arabian Sea
It measure small angles well
Knots where tied when in port to record the latitude so it is a combination instrument and record …no numbers!

6. Other altitude Instruments
A Backstaff improved on the cross staff by allowing the Sun’s altitude to be found without looking at it
A Sextant is complex instrument that measures Altitude very accurately