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.
The Cyanotype, which is also known as ferroprussiate or blueprint was invented by Sir John Herschel in 1842, when he discovered that ferric (iron) salts could be reduced to a ferrous state by light and then combined with other salts to create a blue-and-white image. cyanotype with a blue image on a white background is obtained using a negative transparency. In order to obtain a pale white image on a blue background, a positive transparency must be used. Cyanotypes are created with a simple solution of ferric ammonium citrate and potassium ferricyanide.