Medicare Eligibility. Do you have questions about what it takes to be eligible for Medicare? In this article, weâll outline the Medicare eligibility requirements so that you can enroll in the Medicare program, which is overseen by the Centers for Medicare & Medicaid Services (CMS) via Medicare.gov.
The first compass was invented around 247 B.C. in China and by the eleventh century it was used for navigation.In medieval Europe around 1300 the dry compass was invented and was replaced by the liquid filled magnetic compass in the early twentieth century.A compass is a navigational instrument which is used for determining the direction related to the Earthâs magnetic poles.n medieval Europe around 1300 the dry compass was invented and was replaced by the liquid filled magnetic compass in the early twentieth century. A compass is a navigational instrument which is used for determining the direction related to the Earthâs magnetic poles.
Although sundials have been used since the 8th century B.C., the first individual to be credited with the invention of a sundial is Aristarchus of Samos in about 280 B.C. Aristarchus invented the hemispherical sundial, or hemicycle. It consisted of a block of stone or wood that had a hemisphere-shaped depression cut into it. A pointer was placed on one end of the depression and fixed into place. The path that the shadow followed was approximately a circular arc, hence the name.