Black shells

Shell beads are made om the same material as the pearls themselves, so are naturally nacreous. However, the nacre does not cover the entire bead, but appears in layers due to the structure of the shell (Fig. 10.13). When dyed black, shell beads make convincing imitations of black peails, thou they tend to be too regular in shape. 

Experiments have taken place to see how far from the mortar black shells are likely to fall on the ground. Fig,1 5 shows four examples. (A) is an experiment by the Hosoya Firework Co. on January, 1956, (B) by Tokyo to on February 29th and May 1st,i960, (C) by the same on May l6th ... 

The black shell absorbs this radiation flow completely. It emits the radiation flow A2 T2 itself, of which the proportion F21 strikes body 1. Body 1 absorbs the following radiation flow from the black radiation striking it... 

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