The Thirteenth Floor Trivia Quiz

Answer: The availability of new building technologies

The technologies typically associated with skyscraper construction were not new when the first ones were built in the 1880s. Internal iron frames and non-load-bearing walls had been in use in the USA since the early part of the century on buildings of five and six storeys. Fireproofing by encasing metal in plaster, brick or concrete had been used from the 18th century. Elevators had been known since ancient times and were in regular use in factories. The use of piles in foundations dates to ancient times and caisson technology was imported from Britain in the 1850s.

The architect of New York's Woolworth Building, Cass Gilbert, described the skyscraper as "a machine that makes the land pay" and refers to the idea that economic factors were the spur to build higher and higher.

Answer: Railway tracks

The demand was for office space away from the locations where goods were manufactured, processed or (trans)shipped and the Chicago business district was located close to Lake Michigan on a fork in the Chicago River, in the area which later became known as The Loop.

This area was bounded by a cable-car system at first and later the elevated railway, but in the late 19th century, the huge network of railway tracks over the rest of the city made access to other available land difficult and proved to be a particular problem.

Answer: Metal cylinder filled with concrete

Caissons were provided for each column upon which the building was to be supported and were metal cylinders driven into the ground in sections. Then the earth would be excavated and the cylinder filled with concrete. The technology originally developed from bridge construction where it is still used today.

Layers of concrete of decreasing size were known as "pyramidal piers" and are used today in earthquake areas as they permit the building to move. The "floating raft" developed from the "pyramidal pier" and incorporated iron (later steel) rails into the concrete in each layer at right angles to the one below. The use of log piles was limited by the length and cost of suitable logs and, in areas with a high water table, these had to be topped off with concrete to prevent rotting. Concrete piles were also used.

Answer: Narrow gauge railway tracks

Each floor had a narrow gauge railway track running round the building perimeter. Cars were loaded, lifted by hoist to the correct floor, and driven onto the tracks and thence to the place where they were needed. Girders were unloaded at the correct position for the frame; bricks were deposited next to the bricklayer who needed them.

The use of cars instead of traditional wheelbarrows quadrupled the number of bricks that could be hoisted per trip.

Answer: Metal frames bear the load

Taller buildings need thicker masonry walls to support them, especially at the base. Thicker walls took up more space, which meant that there was less space to rent out, especially at street level where retail outlets were a common feature. In the days before electric lighting, thicker walls also restricted the amount of natural light which could enter and this also was a constraint.

The issue of fireproofing was particularly relevant in Chicago, following the fire of 1871, and precautions such as not building with wood and encasing metal columns and beams in fireproof materials to prevent buckling were introduced.

Answer: Greater percentage of glass windows

Skyscrapers were office buildings and the size of offices was originally determined by how far natural light could penetrate and the need to have opening windows for ventilation. More and bigger windows meant offices could be larger or there could be more of them and this made them more attractive, which in turn meant they could command higher rents.

The other features may have made the buildings more attractive to look at, but would not affect profitablility to the extent that better-lit offices would.

Answer: False

Otis did not invent the elevator but he did add the safety brake, which prevented the car falling to the ground in the event of a cable snapping. At the time, elevators were used for moving freight, but the improved safety would later inspire confidence in the provision of people-carrying elevators in tall buildings.

Simple elevators had been known for about 2000 years and for most of that time had been powered by humans, animals or water wheels. The Industrial Revolution brought steam technology and later hydraulics. The first electrically-powered elevator was built in 1880 by Werner von Siemens.

Answer: Width of the street

The idea of relating the height of buildings to the street width had been used in Europe for some time, but for aesthetic reasons. In New York it was a response to practical problems. The city was zoned into districts with a formula for calculating heights which was a multiple of the street width and an angle of "setback". Thus a "1.5 times district" would permit a first wall rising to 150 feet on a 100 feet wide street but, above this, construction could continue provided it did not protrude beyond the extension of an imaginary line joining the middle of the street to the top of this wall. To keep to this, skyscrapers became "stepped" in appearance. These regulations applied to only three quarters of the site with unlimited height permitted on the rest. If the plot was large enough, it became economically feasible to build a central tower as the rental income would justify the expense of installing lifts and services.

These ordinances gave New York its characteristic skyline, which differed from that of Chicago at the same period. In that city, there was a maximum height for the first wall and unlimited height on a quarter of the site.

Answer: Milam Building, San Antonio

The Milam Building was constructed in 1928 of brick with a concrete frame. Even though they were no longer necessary, the building had windows that opened. The use of air conditioning, combined with fluorescent lighting, led to reductions in the height of rooms which in turn meant more storeys for the same height and increased profit.

Answer: China

The Chinese superstition around the number four derives from its pronunciation being very similar to that for the word for "death". As well as omitting the number from floor levels, a four in an address can adversely affect the value of property.

The lack of a thirteenth floor in many buildings has given rise to suspicions about actual uses and has entered popular culture in the form of urban myths, films, sci-fi literature and television programmes. According to the Otis lift manufacturers, as many as 80% of lifts do not have a floor designated 13.