Physics and Star Wars
To estimate the effects of the second Death Star, Minton looks into its mass. According to estimated data from some students of Lehigh University, the steel mass needed for building one would be around 770 kilograms times the mass cubed in weight. This would give the Death Star of about ten to the power of nineteen kilograms in mass. Using this data, Minton produces equations that lead him to conclude the fragments would hit the moons surface so hard causing craters almost four times the size of the Chicxulub crater in Mexico. This impact would cause a planetary firestorm and vaporize all lifeforms on the moon.
Jackass-barque
A well-known example of a steel four-masted jackass-barque was the "California" (1890), the last and largest of the White Star sailing ships. The use of steel enabled the addition of another hundred feet to the two hundred foot effective maximum length of a wooden vessel. A fourth mast, called the jigger, provided the driving power for the increased length. The lower and topmast were built in one steel tubular piece. Mechanical improvements were introduced to the rigging.