The city struck fortune in the late 18th century with the inventions and industrial activity of Eli Whitney, a Yale graduate who remained in New Haven to develop the cotton gin and establish a gun-manufacturing factory in the northern part of the city near the Hamden town line. That area is still known as Whitneyville, and the main road through both towns is known as Whitney Avenue. The factory is now the Eli Whitney Museum, which has a particular emphasis on activities for children and exhibits pertaining to the A. C. Gilbert Company. His factory, along with that of Simeon North, and the lively clock-making and brass hardware sectors, contributed to making early Connecticut a powerful manufacturing economy; so many arms manufacturers sprang up that the state became known as "The Arsenal of America". It was in Whitney's gun-manufacturing plant that Samuel Colt invented the automatic revolver in 1836. The Farmington Canal, created in the early 19th century, was a short-lived transporter of goods into the interior regions of Connecticut and Massachusetts, and ran from New Haven to Northampton, Massachusetts.
Who is the Yale graduate, inventor, and arms manufacturer that had a large positive impact on the New Haven economy in the late 18th century?
Eli Whitney

In 1906, precipitation hardening alloys were discovered by Alfred Wilm. Precipitation hardening alloys, such as certain alloys of aluminium, titanium, and copper, are heat-treatable alloys that soften when quenched (cooled quickly), and then harden over time. After quenching a ternary alloy of aluminium, copper, and magnesium, Wilm discovered that the alloy increased in hardness when left to age at room temperature. Although an explanation for the phenomenon was not provided until 1919, duralumin was one of the first "age hardening" alloys to be used, and was soon followed by many others. Because they often exhibit a combination of high strength and low weight, these alloys became widely used in many forms of industry, including the construction of modern aircraft.
When were precipitation hardening alloys discovered?
1906

Under the early courts, when military conscription had been centrally controlled, military affairs had been taken out of the hands of the provincial aristocracy. But as the system broke down after 792, local power holders again became the primary source of military strength. The re-establishment of an efficient military system was made gradually through a process of trial-and-error. At that time the imperial court did not possess an army but rather relied on an organization of professional warriors composed mainly of oryoshi, which were appointed to an individual province and tsuibushi, which were appointed over imperial circuits or for specific tasks. This gave rise to the Japanese military class. Nonetheless final authority rested with the imperial court.
Where did final authority over the military lie?
imperial court