Passage: Originally, the statue was a dull copper color, but shortly after 1900 a green patina, also called verdigris, caused by the oxidation of the copper skin, began to spread. As early as 1902 it was mentioned in the press; by 1906 it had entirely covered the statue. Believing that the patina was evidence of corrosion, Congress authorized US$62,800 (equivalent to $1,751,000 in 2018) for various repairs, and to paint the statue both inside and out. There was considerable public protest against the proposed exterior painting. The Army Corps of Engineers studied the patina for any ill effects to the statue and concluded that it protected the skin, "softened the outlines of the Statue and made it beautiful." The statue was painted only on the inside. The Corps of Engineers also installed an elevator to take visitors from the base to the top of the pedestal.On July 30, 1916, during World War I, German saboteurs set off a disastrous explosion on the Black Tom peninsula in Jersey City, New Jersey, in what is now part of Liberty State Park, close to Bedloe's Island. Carloads of dynamite and other explosives that were being sent to Britain and France for their war efforts were detonated, and seven people were killed. The statue sustained minor damage, mostly to the torch-bearing right arm, and was closed for ten days. The cost to repair the statue and buildings on the island was about US$100,000 (equivalent to about $2,300,000 in 2018). The narrow ascent to the torch was closed for public-safety reasons, and it has remained closed ever since.That same year, Ralph Pulitzer, who had succeeded his father Joseph as publisher of the World, began a drive to raise US$30,000 (equivalent to $691,000 in 2018) for an exterior lighting system to illuminate the statue at night. He claimed over 80,000 contributors, but failed to reach the goal. The difference was quietly made up by a gift from a wealthy donor—a fact that was not revealed until 1936. An underwater power cable brought electricity from the mainland and floodlights were...

Question: Who completed the study on the patina?
The Army Corps of Engineers