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.
The first Fresnel lens was used in 1823 in the Cordouan lighthouse at the mouth of the Gironde estuary; its light could be seen from more than 20 miles (32 km) out.[15] Fresnelâs invention increased the luminosity of the lighthouse lamp by a factor of 4 and his system is still in common use.