Michael Stecker in basement of 18231 Stoepel, Detroit, Michigan.  The cement sink (labeled) was destroyed with one weighted Silver Salute firecracker when it sunk to the bottom of the water filled sink and exploded.  A good example of how uncompressible
water is and how it facilitates the transfer of energy to the walls of a vessel.  This principle was used by the British in World War II to destroy German dams (ref.).
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Silver Salutes
Similar to red M80s, but silver in color. They look and feel just like the original silver salute and contain the maximum legal amount of flash powder allowed by law for consumer firecrackers (50 mg).

The Silver Salutes of today are far less powerful than the ones I used in the 1950s.  Like Cherry Bombs and M80s their  explosive fuel is flash powder -- a mixture of Potassium Perchlorate (oxidizer) aluminum powder and sulfur.  My "homemade" firecrackers used a more powerful flash powder because the aluminum powder was replaced with magnesium powder.  This metal produces much more energy (heat and light) when burned than aluminum.
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You can purchase Silver Salute at:
http://www.usfireworks.biz/items/fcf1003.htm
ref.: http://en.wikipedia.org/wiki/Silver_Salutes#Silver_Salute_or_Ashcan

This was also the location where I first made and tested nitroglycerin.