K-12 Teaching and Learning From the UNC School of Education

LEARN NC was a program of the University of North Carolina at Chapel Hill School of Education from 1997 – 2013. It provided lesson plans, professional development, and innovative web resources to support teachers, build community, and improve K-12 education in North Carolina. Learn NC is no longer supported by the School of Education – this is a historical archive of their website.

About this diagram

Image credit

Provider
NASA
Date created
2003
License
This work is believed to be in the public domain. Users are advised to make their own copyright assessment and to understand their rights to fair use.

See this diagram in context

  • North Carolina in the New Nation: Primary sources and readings explore North Carolina in the early national period (1790–1836). Topics include the development of state government and political parties, agriculture, the Great Revival, education, the gold rush, the growth of slavery, Cherokee Removal, and battles over internal improvements and reform. (Page 7.4)

Related media

Learn more

In the classroom

  • See our collection of articles on visual literacy for ideas on using photographs meaningfully in the classroom.
diagram of a mercurial thermometer

Based on a principle developed by Evangelista Torricelli in 1643, the Mercurial Barometer is an instrument used for measuring the change in atmospheric pressure. It uses a long glass tube, open at one end and closed at the other. Air pressure is measured by observing the height of the column of mercury in the tube. At sea level, air pressure will push on the mercury at the open end and support a column of mercury about 30 inches high. If you used water instead of mercury, you would need a glass tube over 30 feet in length.

As atmospheric pressure increases, the mercury is forced from the reservoir by the increasing air pressure and the column of mercury rises; when the atmospheric pressure decreases, the mercury flows back into the reservoir and the column of mercury is lowered.