Circle of latitude the Earth onto a plane. On an equirectangular projection, centered on the equator, the circles of latitude are horizontal, parallel, and equally spaced. On other cylindrical and pseudocylindrical projections, the circles of latitude are horizontal and parallel, but may be spaced unevenly to give the map useful characteristics. For instance, on a Mercator projection the circles of latitude are more widely spaced near the poles to preserve local scales and shapes, while on a Gall–Peters projection the circles of latitude are spaced more closely near the poles so that comparisons of area will be accurate. On most non-cylindrical and non-pseudocylindrical
Latitude ON a customizable, Linux-based Mobile Internet Device (MID) platform the laptop is able to boot almost instantly and view Email, document reader, calendar, contacts and access the Internet. First laptop models to include Latitude ON were E4200 and E4300 released in February 2009. Last laptop model introduced so far is Latitude Z600. Dell claims that battery life can be extended to days. Latitude ON Reader is similar to Dell's MediaDirect where the software is located in a separate partition on the system hard drive and has a dedicated button to power on. There are several versions of Latitude ON: Latitude ON