Likewise, if the population consists of equal numbers of males and females, and if the females give birth to 3 children each (and the males 0), then the average birth rate of the population will be 1.5. With these basics we can now consider two simple models of population growth:
For most purposes scrolls have long been superseded by the codex book format, but they are still produced for some ceremonial or religious purposes, notably for the Jewish Torah scroll for use in synagogues.
The purpose of the wood dowel and the scroll ends is to provide weight so that, when the scroll was unrolled and hanging, it would lay flat and the painting could be easily viewed. The upper piece of wood served the same purpose but was thin so as to make a neat package when the scroll was rolled up and tied.