Which of the following part of the flame does a goldsmith use to melt out gold or silver?

Goldsmiths blow the outermost zone of a

flame

in order

to melt gold

or silver because the

outermost

zone

is

a zone of complete combustion, also known as the luminous zone. The ignition temperature of this zone

is

the highest and thus helps in

melting

the metal the best in order to create desired designs or patterns.