METALLISING FLOWERS & INSECTS.

Dunstan Times, Issue 2479, 3 May 1909, Page 8

METALLISING FLOWERS & INSECTS.

Mr T. C. Hutchinson, who invented the process of reproducing flowers, leaves, insects, and other like objects, in metal, describes it in The Keystone, a jewellers’ journal published in Philadelphia. Oddly enough, the inventor conceived the idea from a speech mado by an Irish dentist at a convention dinner. The dentist said humorously: —“I am going to quit dentistry and take up the manufacturing jewellers’ business. I am going to hire a lot of children to go into the woods and catch beetles, then to bring them to the factory, where I shall stick pins into them, invest them, and burn them out (no residue) and force metal into the form made vacant by the burning.” The inventor goes on: —“This, ip a nutshell, is my method of reproducing animal and vegetable matter in metal, differing only in that where flowers or leaves are to be cast, I use the stem of said flower or leaf as a sprue instead of a pin. While my friend little thought it possible to accomplish what he said, yet it is true that the finest lines of the flower, viz., the ribs, stamen, and the hair-like parts of the moss rose, or the antenna; or legs of the butterfly, can be reproduced with this new method of casting with pressure. I will in a few words tell what the dentist of to-day is doing along these lines, and from this you will readily recall by your imaginative powers the many places in which this casting with pressure will be useful to you in your work. The dentist prepares a cavity in a tooth that is to be filled, with no under-cuts; he then takes wax and fills said cavity, packs it full and trims off the surplus, so that it will be just as he wants his gold or silver filling to be; ho then takes it out of the cavity, puts it on a sprue-pin, and then places the pin in a crucible former, then puts a metal ring or flask over this and pours investment material, filling it up to the top of the ring. This investment material is composed of two parts silica and one part plas-ter-of-Paris. After this begins to set the crucible former and pin are removed, this then leaves the investment with a concave surface with the sprue or hole reaching to the wax. The next procedure is to heat over a Bunsen burner slowly until the investment is freed of moisture, then the blow-pipe is used to hasten heating and to burn out the wax. When this is accomplished the metal nugget is placed in the crucible and melted to a white heat. The flask is brought in position under the metal disk of the casting machine, the latter is pressed downward upon the flask and, in so doing, automatically lots in the air, forcing the molten metal to place. This operation takes about twenty-five minutes. The size of the wax object to be reproduced makes little difference. If it is possible for a dentist to accomplish this, it is possible to reproduce any form of wax, animal or vegetable matter into metal. Wax burns out with the ordinary hea from a Bunsen, while the flower, or the like, requires a blast heat to burn tip the ashes, etc. Inasmuch as vegetable and animal matter are largely composed of water, especially the former, evaporation by heat removes the bulk of the invested flower, etc. There are many castingmachines now used, having different methods of producing pressure, viz., the air, steam, vacuum, and centrifugal force machines. I have used them all, and while any one of these will accomplish ordinary work, yet I favor the air machine for doing extensive work. The clover leaf, not much thicker than newspaper, requires much more force to cast than a rose.”