Here is an interesting little "tid-bit"...

prior to detonating the first "gadget" atomic device, the scientists put together a 100 ton "test" to calibrate their instruments for what they hoped would be the yield of the device. While the total "tonnage" was above the first atomic device estimate, the effects were very different.

Goto:

http://nuclearweaponarchive.org/Usa/Tests/Trinity.html

The most recognized alteration was in the "heat" delivered to the sand, the tons of "normal" explosive named Composition B (TNT/RDX), it did little to the sand, the atomic turned it into glass. The "normal" explosive created a very small crater, the atomic device made a much larger one with less estimated explosive power. This was a very different device from all the others the world had ever known, but just what it was remained a mystery (sadly) for decades.

For our American rogues, or those who have access to Hulu, here is a link to that movie mentioned Trinity and Beyond. Sorry it doesn't work for everybody.

Goto:

http://www.hulu.com/watch/225009/trinity-and-beyond