Tire placard pressure is often much lower than listed on the tire sidewall. Air pressure given by the vehicle maker was based on the tires supplied with the vehicle. They design many newer replacement tires to give a good ride, with much more pressure.
Fresnel lens. A Fresnel lens is a type of lens invented by Augustin-Jean Fresnel. Originally developed for lighthouses, the design enables the construction of lenses of large size and short focal length without the weight and volume of material which would be required in a lens of conventional design. Detailed information.
Historians credit the invention of the compound microscope to the Dutch spectacle maker, Zacharias Janssen, around the year 1590. The compound microscope uses lenses and light to enlarge the image and is also called an optical or light microscope (vs./ an electron microscope).