Where can you buy cheap text books for school online?

if they are homeschool books you might try www.vegsource.com/homeschool

I just checked and they indicate they sell text books. Good luck!

Check out http://www.bookuet.com to find best prices on all sorts of books. You can compare prices for new and used copies at multiple online stores including amazon, ebay, half.com.

http://www.half.ebay.com/ http://www.powells.com/

...wait a second or two and then slide your hand up and down the tank. It will remain quite hot where there is no propane behind the steel wall of the tank, however the heat will be rapidly absorbed from the tank surface by liquid propane. So, you can tell where the liquid level is by feeling the temperature gradient on the tank surface with your hand. Where the tank goes from hot to cold is where the liquid level is.