They were magnificent, powerful creatures in varying hues of gold and brown.
None of the Petrels are endowed with any brilliant colouring - sootyblack, grey of various tints (one of which is often called "blue"), and white being the only hues the plumage exhibits.
Copper, too, by patina-producing treatment, is made to show not merely a rich golden sheen with pleasing limpidity, but also red of various hues, from deep coral to light vermilion, several shades of grey, and browns of numerous tones from dead-leaf to chocolate.
Sometimes in the same design we see gold of three different hues, obtained by varying the alloy.
Copper, tin, lead and zinc, mixed in various proportions by different experts, are the ingredients, and the beautiful golden hues and glossy texture of the surface are obtained by patina-producing processes, in which branch of metal-work the Japanese show altogether unique skill.