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Birch bark tar use as an adhesive began in the Middle Paleolithic. Neanderthals produced tar through dry distillation of birch bark as early as 200,000 years ago. [6] A 2019 study demonstrated that birch bark tar production can be a simpler, more discoverable process by directly burning birch bark under overhanging stone surfaces in open-air conditions. [7]
The Romans first used hydraulic concrete in coastal underwater structures, probably in the harbours around Baiae before the end of the 2nd century BC. [12] The harbour of Caesarea is an example (22-15 BC) of the use of underwater Roman concrete technology on a large scale, [10] for which enormous quantities of pozzolana were imported from ...
Roman Catholic historian Francis Dvornik argues that the pope accepted the acts of the council and annulled those of the Council of 869–870. Other Catholic historians, such as Warren Carroll, dispute this view, arguing that the pope rejected the council. Siecienski says that the Pope gave only a qualified assent to the acts of the council. [4]
Most famous was Parker's "Roman cement". [25] This was developed by James Parker in the 1780s, and finally patented in 1796. It was, in fact, nothing like material used by the Romans, but was a "natural cement" made by burning septaria – nodules that are found in certain clay deposits, and that contain both clay minerals and calcium carbonate.
The upper cover is late Carolingian work of about 880, and the text of the gospel book itself was written and decorated at the Abbey of Saint Gall around the same time, or slightly later. [ 1 ] When J.P. Morgan , already in his early sixties, bought the book in 1901, it was his first major purchase of a medieval manuscript, setting the ...
A typical PSA tape consists of a pressure-sensitive adhesive (the sticky part of the tape) coated to a backing material. To prevent the adhesive from sticking to the backing when wound in a roll, a release agent is applied to the backing or a release liner is placed on the adhesive. Sometimes a primer is coated between the adhesive and backing ...
The ruling comes after dozens of people filed civil lawsuits against the Roman Catholic Bishop of Portland alleging they were sexually assaulted as children by the clergy, with allegations going ...
Ancient boat building methods can be categorized as one of hide, log, sewn, lashed-plank, clinker (and reverse-clinker), shell-first, and frame-first.