Short-term disability insurance, which is most often purchased as part of a group at work, can be paid by either the employer or the employee. Group short-term disability insurance policies are guaranteed issue, meaning you do not have to take a medical exam to buy coverage.
In 1650, Otto von Guericke invented the air pump, used to create a partial vacuum. Using hollow copper spheres and an air pump of his own construction, Guericke demonstrated that a partial vacuum could be created by pumping the air out of the sphere.
First, in 1856, Henry Bessemer patented his converter process for blowing air through molten pig iron, and in 1861 William Siemens took out a patent for his regenerative open-hearth furnace. In 1879 Sidney Gilchrist Thomas and Percy Gilchrist adapted the Bessemer converter for use with phosphoric pig iron; asâ¦