The circa 54 - 56-year Saros Cycle
was known to the Egyptians and Babylonians.

It represents a combination of three
circa 18-19 year cycles
in which all eclipses
between the moon, earth and Sun recur.

These are also the 56 Aubrey holes at Stonehenge,
as pointed out by Gerald S. Hawkins in
Stonehenge Decoded
(Doubleday & Co., Inc: Garden City, N.Y., 1965.

This same cycle (known as the Kondratieff Cycle)
was "rediscovered" in modern times
by N.D. Kondratieff,
who found this cycle mirrored in many economic phenomena.

One of the best known examples of this cycle
was found by Lord Beverage,
who proved such a cycle in European
wheat prices from 1500 to 1869.

A similar cycle has also been found in various other phenomena:
in the thickness of tree rings
(the study of tree rings is called dendrochronology),
in the amount of river run off, in varves
(varves are sedimentary rock or mud deposits),
in stock prices
and in international battles and wars.

And here, to the great surprise of many
we can add one more cycle to the list of phenomena
which abide by the Kondratieff-Saros period, namely,
the years of birth of eminent persons in the
Micropaedia edition of the Encyclopaedia Britannica.

The graphs above use the price of consumables
in Southern England 1700-1900 for comparison,
since this cycle is regarded to be the best established
and documented of the Kondratieff Cycles.

The three curves in the graphs are:

1) the number of persons born, departures from trend,
9-year moving average; standard deviations;
2) the price of consumables in Southern England (idealized), and;
3) the price of consumables in Southern England,
departures from trend, as taken from Gertrude Shirk,
"Another Item in the 54-Year Cycle Study", CYCLES,
Volume XXVI, No. 3, 1975, pp. 69-76,
Foundation for the Study of Cycles, Pittsburgh, USA.