Who is Louis Agassiz

Louis Agassiz was a great Swiss naturalist. He was born in 1807, and when he grew up he became a professor of natural history. He led many exploring expeditions all over the world, and be­came known for his studies of animals, glaciers, and other things in nature. In 1846 he settled in the United States. He died in 1873. Mount Agassiz, in New Hampshire, and Lake Agassiz, a prehis­toric lake in the Northwest, are named for him. agate Agate is a hard stone, a kind of quartz, that is formed in streaks or layers of different colors. It is trans­lucent, which means that the light shines through it, and it is very hard and can be polished to a shining surface. All this makes agate very beautiful, and it is used in many ornaments, the very fin­est agate being made into settings for rings and pins and brooches, and being classed as a semiprecious stone.

There is no limit to the number of different patterns formed by the many colors in agate, but the principal kinds are called banded agate, which has wavy layers of different colors; clouded agate, which has patches of color; and moss agate, which has dark marks that look like moss or ferns. In some pieces of agate the layers of color form rings that look like an eye, and people in Oriental countries sometimes used to cut this into the shape of an eye and wear it on a chain around the neck, calling it "the evil eye"; they thought it would drive away evil spirits that might attack them. There is a great deal of agate in the world, and as a stone it is not very ex­pensive. That is the reason children's marbles can be made out of it and sold for quite low prices (though of course they do cost much more than glass marbles). The cost of fine agate is mostly in the cutting of it. Agate is found in Brazil and Uruguay in South America, in India, and in the United States around Lake Superior.