<Tr> <Th> Material </Th> <Th> Bore (in) </Th> <Th> Len (in) </Th> <Th> Wt (lb) </Th> </Tr> <Tr> <Td> 6 - pounder Gun </Td> <Td> bronze </Td> <Td> 3.67 </Td> <Td> 60 </Td> <Td> 884 </Td> <Td> 6.1 </Td> <Td> 1.25 </Td> <Td> 1,439 </Td> <Td> 1,523 </Td> </Tr> <Tr> <Td> M1857 12 - pounder "Napoleon" </Td> <Td> bronze </Td> <Td> 4.62 </Td> <Td> 66 </Td> <Td> 1,227 </Td> <Td> 12.3 </Td> <Td> 2.50 </Td> <Td> 1,440 </Td> <Td> 1,619 </Td> </Tr> <Tr> <Td> 12 - pounder Howitzer </Td> <Td> bronze </Td> <Td> 4.62 </Td> <Td> 53 </Td> <Td> 788 </Td> <Td> 8.9 </Td> <Td> 1.00 </Td> <Td> 1,054 </Td> <Td> 1,072 </Td> </Tr>

What were cannons made of in the civil war