Your work on measuring atmospheric pressure has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
your comment
How does the system behave and how does it 'feel'?
When i squeeze the bottle, water travels up the vertical tube and the water in the pressure tube moves. The more force I use, the further the water travels in the pressure tube. It is fairly easy to get the water to travel up the vertical tube and to move it in the pressure tube.
Length of the air column in units of your measuring device:
I chose the full size to measure with because it is the easiest for me to read.
Your report of the vertical position of the first mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials.
33.5cm
I measured the bottom of the miniscus and lined the tube along the ruler till I reached the glue pug and here is where i took my final measurement.
Your report of the vertical position of the second mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials.
10cm
33.5cm
18.9,19.2
19.0,19.2
18.95,19.25
18.95,19.25
18.95,19.25
Your report of the vertical position of the highest mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials.
18.95,19.55
19.00,19.54
19.05,19.58
19.05,19.55
19.00,19.53
Your report of the vertical position of the 'in-between' mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials.
19.00, 20.05
19.05, 20.07
19.00, 20.05
19.05, 20.1
19.05 20.05
19.05, 19.65
19.05, 19.70
19.05, 19.68
19.05, 19.65
19.05, 19.70
You appear to have good data to carry forward to Part 2 of this experiment.