They were also active in the development of many other technologies such as textile weaving, locks and canals, flood control, water storage and irrigation. Sometimes known as the "Second oldest profession", soldering has been known since the Bronze Age (Circa 3000 to 1100 B. A form of soldering to join sheets of gold was known to be used by the Mesopotamians in Ur.There are also claims that the Archimedes' Screw may have been invented in Mesopotamia and used for the water systems at the Hanging Gardens of Babylon. Fine metal working techniques were also developed in Egypt where filigree jewellery and cloisonné work found in Tutankhamun's tomb dating from 1327 B. was made from delicate wires which had been drawn through dies and then soldered in place. Fine wire also made by the Egyptians by beating gold sheet and cutting it into strips. Around this date, after his escape from Egypt, Moses ordered the construction of the Ark of the Covenant to house the tablets of stone on which were written the original "Ten Commandments".
The following rules are attributed to him: Using the concept of similar triangles he was able to calculate the height of pyramids by comparing the size of their shadows with smaller, similar triangles of known dimensions.Produced from the freshwater papyrus reed, the papyrus scrolls were fragile and susceptible to decay from both moisture and excessive dryness and many of them have thus been lost, whereas the older, more durable clay cuneiform tablets from Mesopotamia have survived. Sumerian mathematics and science used a base 60 sexagesimal numeral system.Historians seem to agree that the wheel and axle were invented around 3500 B. 60 is divisible by 1,2,3,4,5,6,10,12,15,20,30 and 60 making it more convenient than using a base 10 decimal system when working with fractions.Since the average lunar month is 29.5 days, over 12 months this would produce a total of only 354 days as against a solar year of 365.25 days.To keep the calendar aligned to the seasons they added seven extra months in each period of 19 years, equivalent to the way we add an extra day in leap years.