This is a major handicap that made them all but useless to astronomy. The information is stored on disk and the nightly observations can be added with a computer to give long integration times. Having concluded that it would be worthwhile to explore again the liquid mirror concept Ermanno Borra began a feasibility study to determine whether, in practice, it is possible to generate an optical quality surface on a spinning liquid. This was followed by tests of a 2.5-m mirror. The construction of a 5 meters diameter mirror is under way for this same survey.
Liquid mirrors are interesting in other areas of science besides astronomy.