Ice core sampling normally uses the assumption that the ring bands observed represents years.
One known example where this assumption was used is very misleading.
During this time, the area was a savanna and supported numerous animals such as extinct buffalo and large giraffes, varieties of antelope and gazelle.
Beginning around the 10th millennium BC, this region of the Nubian Desert began to receive more rainfall, filling a lake.
The two photos at the bottom show one of the plate casting machines called a Pony autoplate and could turn out 1 plate a minute. The gentleman with presentation front page plate is Eddie Hunter one of Alf Spearings staff. The slide rule is used mainly for multiplication and division, and also for "scientific" functions such as roots, logarithms and trigonometry, but usually not for addition or subtraction. These scales are used for mathematical computations. They have a standardised set of markings (called scales).Before electronic calculators were developed, slide rules were the tool used most often in science and engineering.The use of slide rules continued to grow through the 1950s and 1960s even as digital computing devices were gradually introduced; but around 1974 the pocket calculator made the slide rule largely obsolete and most suppliers left the business.
In its most basic form, the slide rule uses two logarithmic scales to allow rapid multiplication and division of numbers.