Topo Maps for the L. M. Nixon Barometer Project.
rev. 4-22-06

Here are the various maps you will need to calibrate your barometer.  First, we have a vector map and a topo map (topographic map) for the immediate vicinity of Nixon School.  Work with your teacher, your fellow students or your parents to find the elevation (above mean sea level) for Nixon School.  The elevation is about 140 feet; make sure you know how this was determined from the topo map.

How to Use the Topo Map.

1.  Find one of the topo lines near Nixon school that is marked "200", or 200 feet above means sea level.  Everything on this line is at the same 200 foot elevation.  Identify it by carefully tracing over this line with a fine-point marker.

2.  Next find one of the topo lines near Nixon school that is marked "100", or 100 feet above mean sea level.  Identify it in the same way that you did for the 200 foot elevation.

3.  Look carefully at the map and the space between the 100 and 200 foot lines of equal elevation.  You will see several other lines in this space.  You should see 4 other lines in the space between the 100 and 200 foot lines,  These lines represent 20 foot intervals between 100 feet and 200 feet.  So find the 120 foot, 140 foot, 160 foot and 180 foot elevation lines.  See which line is closest to Nixon school.



Maps from Hwy 280 to Skyline Blvd. along Page Mill Road

Page Mill North (3.6 MB .pdf file)
Page Mill South (3.6 MB .pdf file)

Get the free Adobe .pdf file reader here if you do not already have one:



Our most recent versions of the topo maps have been simplified and condensed to fit on two legal-sized pages and display the route along Page Mill Road from Hwy. 280 to Skyline Blvd. Various landmarks are included to help in locating the elevations in 250 foot increments. I know, I know, you want all the measurements in the metric system. Well, I do too, but the reality is that we "United States-eans" are still stuck in the English system so we'll work with that for now.

As you try to use the topo maps, remember that, in the flatlands, each topo line may be separated by only 10 feet.  But in the mountains, each topo line may be separated by 40 or more feet.  So you will need to look for the heavier, labelled topo lines and count between them.

All of the maps that we have displayed are the property of the USGS and have been "grabbed" from the website of  Map Mart (www.mapmart.com) and are used for educational classroom purposes only.  They are not to be reproduced for commercial sale.

If you'd like to collect your own topo maps, start at this link on the Map Mart website and then use the tool box menus on the Map Mart site to zoom in to Palo Alto, CA if you are a Nixon student (the exact GPS coordinates for the starting point are 37.389 Latitude, -122.163 Longitude if you are interested).


Using Google Earth With Our Topo Maps

Google Earth is pretty new at this writing and is an amazing tool. It has some very useful features and some weaknesses for our purposes. We really need two things in our project: we need to know where we are and we need our elevation when we get there. Just because you have a map in your hands as you drive up a winding mountain road does not mean that you can determine where you are on the map. Landmarks, road signs, distinct bends in the road are essential for this task. If you happen to have a Global Positioning System (GPS) device, and Google Earth, then you are all set. We have added GPS coordinates for the various elevation locations on our Page Mill maps.

Google Earth also gives elevations;  Google Earth has weaknesses here. Topo maps are made from a composite process that combines data from stereoscopic aerial photographs and accurate altitude measurements at discrete benchmark locations. While the actual topo lines may therefore not be extremely accurate, the benchmark measurements are accurate to one foot or better. This is where Google Earth fails; when Google Earth is used to scan benchmarks, Google is often in error. However, even the best of the student barometers, when used with the greatest of care, is readable to only 50 feet and accurate to probably 150 feet.  So what we can say about our topo maps is that  you will know exactly where you are, but you may know your elevation to only within 50-100 feet where the grade is substantial.