Copper was introduced because the iron nails under the copper sheathing, when it came in, caused electrolytic action between the two metals which damaged the sheathing.
Ikopolo yaziswa kuba izikhonkwane zentsimbi ngaphantsi kwesingxobo sekopolo ca yayingena zenza isenzo sombane phakathi kwezinyithi ezibini ezonzakalisa isingxobo.