Because of the short tubes, early binoculars were constructed with the Galilean lens arrangement and are called Galilean-type binoculars. The double-convex objective and double-concave eyepiece, results in powers little better than 3 to 4x., providing an inferior contender to the multi-lens, higher power terrestrial telescopes. It wasn’t until the late 1800s when creative designs began to appear and people began to appreciate the compactness and convenience of binoculars that they were produced in quantity as ‘field glasses’. For example, in the 1880s ‘telescoping’ binoculars with 4 lenses in the eyepiece tube were offered. These long binoculars are basically two Schyrle-type telescopes mounted in parallel. Some are large but lightweight, with aluminium bodies, and can magnify up to 16x. They were popular in the military during the World Wars. By the late 1800s refinements on some binoculars included sling loops for straps, sunshade cylinders and hinged bridges or ‘bosses’ to adjust for differences in eye separation from user to user. Aluminium construction rather than heavier brass was becoming more common.