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Methods and techniques of construction in the 18th century were a combination of medieval and experimental techniques.

A century earlier, the stage was set for improvements in building construction to come. Though many of the methods used in that time were still medieval, there was an increase in the use of tools (some outdated now by modern technology) but some that are still in use today, including; the compound pulley, line gauge, plumb-line, carpenter's square, spirit level, and drafting compass.

 

Many major breakthroughs - pushed forward by experimental science in the seventeenth century - began to inform the form, shape, and design of buildings. It’s known that seventeenth century construction techniques still relied heavily on trade-sharing rules of thumb and widespread use of scale models before building. Sizes of members were, also, not calculated until the 18th century.

As we entered the 18th century, architects became more professionalized. Though many of the same techniques from the previous century were still in use, a few more experimental buildings were constructed with suspended floor beams. Iron rods were also used to repair the Salisbury Cathedral and strengthen the dome of St Paul's Cathedral. This was due, in part, to the decreasing costs of iron production which allowed for major iron-engineering projects. Use of iron included; cast-iron to carry brick vaults for floors, and the use of wrought-iron for roofs – as seen at the Louvre in Paris. Louis Lucas de Nehou and A. Thevart’s perfection of polished plate glass in France in 1688 ushered in a new era. The technique was further refined in 1773 in Ravenhead, England and informed the design of new buildings across the region.

In the eighteenth century, steel was being used in the manufacture of tools but was not yet made in sufficient quantities to be used for building. It would take until the mid-19th century for steel to be used in combination with I-beams and reinforced concrete for large-scale construction.

A book on crane technology, The Construction of Cranes and Other Lifting Machinery, by Edward Charles Robert Marks, published in 1904, devoted half of its pages to detailed information on manually operated cranes. In the 18th century, cranes were at times even installed inside the buildings as they were being constructed. They would start on the ground, and as the construction work proceeded, they would be dismantled and reassembled multiple times both upwards and outwards. Sometimes when buildings were finished, cranes were left above the vaulting and below the roof where they might come in handy for repairs. Nowadays all but the most dedicated architectural ecologists are using fossil-fuel powered cranes and other heavy construction machinery – with increased speed and precision.

Flying scaffolding, a type of staging suspended by ropes or cables from outrigger beams attached at the top of a structure, was employed at St Paul's Cathedral in England and in the building of the dome of St Peters in Rome. Aside from these two known cases, the same types of timber scaffolding common in the 17th century were still in heavy use. For the most part, both scaffolding and cranes depended on timber for their construction and builders also made use of complex pulley systems that allowed for the lifting of comparatively large loads by relatively fewer workers. Additionally, long ramps were used to haul loads up to the top parts of buildings.

18th century construction, and decorative advancements like sheet glass, coupled with the beginning of the industrial revolution and in increase in brick manufacture, pushed  both the pace of construction projects and the expansion of cities.