Engineering Commons^™

Up to the Middle Ages, seven metals were only known and used by man. These were gold, silver, copper, iron, lead, tin, and mercury. During the Middle Ages the metalloids arsenic, antimony, and bismuth were isolated as well as zinc that was imported from the East. In the Eighteenth century mineral specimens were continuously supplied and analyzed which resulted in the discovery of about a dozen new metals. With the discovery of electric current at the beginning of the nineteenth century the alkali metals were isolated and these were responsible for the isolation of new metals that were not possible …

Postage stamps are important means of communication and many countries have recorded important events, honored worthy individuals, and described interesting facts through this medium. Many historical facts, sometimes obscure, can be found on stamps; some of these may not be easily located in a history or a science book. Stamps have artistic value, they are created by artists. Mining and Metallurgy on Postage Stamps is intended to give a historical background to mining and metallurgy by presenting about 900 enlarged reproductions of colored stamps from different countries. Explanations are given in simple language to bring these topics to young people, …