LiorLefineder Profile picture
Jul 12 7 tweets 3 min read Read on X
Ruina montium, "wrecking of mountains", A Roman mining technique in which pressurized water was used to crack mountain walls.
Pliny's description: "The third method will have outdone the achievements of the Giants. By means of galleries driven for long distances the mountains are mined by the light of lamps—the spells of work are also measured by lamps, and the miners do not see daylight for many months.

The name for this class of mines is arrugiae; also cracks give way suddenly and crush the men who have been at work, so that it actually seems less venturesome to try to get pearls and purple-fishes out of the depth of the sea: so much more dangerous have we made the earth!"Image
"Las Médulas, the most important gold mine in the Roman Empire. The spectacular landscape resulted from the ruina montium mining technique" Image
More from Pliny:
"there is a kind of earth consisting of a sort of potter's clay mixed with gravel, called gangadict, which it is almost impossible to overcome. They attack it with iron wedges and the hammer-machines mentioned above; and it is thought to be the hardest thing that exists, except greed for gold"Image
"The fractured mountain falls asunder in a wide gap, with a crash which it is impossible for human imagination to conceive...The miners gaze as conquerors upon the collapse of Nature. And nevertheless even now there is no gold so far, nor did they positively know there was any when they began to dig; the mere hope of obtaining their coveted object was a sufficient inducement for encountering such great dangers and expenses."Image
"According to some accounts Asturia and Gallaecia and Lusitania produce in this way 20,000 pounds weight of gold a year, Asturia supplying the largest amount. Nor has there been in any other part of the world such a continuous production of gold for so many centuries. "
"Another equally laborious task involving even greater expense is the incidental operation of previously bringing streams along mountain-heights frequently a distance of 100 miles for the purpose of washing away the debris of this collapse... At the head of the waterfall on the brow of the mountains reservoirs are excavated measuring 200 feet each way and 10 feet deep. "Image
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More from @lefineder

Jul 3
Since the invention of exact perspective in the 1420s, which was followed by other artistic innovations, the price of paintings in Renaissance Italy tripled.
This is true even when controlling for characteristics of the painting and who painted them, indicating that the increase in the quality of paintings driven by these innovations was driving up demand, making paintings more profitable.Image
"The expected compensations of a young apprentice (unaware of his future talent) were increasing during the fifteenth century. But a similar increase in profitability also applies conditioning on the talent of the painter...reaches levels in the 1480s that are about three times those of the 1420s."Image
"This evolution suggests a Schumpeterian pattern. Part of the artistic creativity associated with Renaissance, and the artistic innovations of this period, such as the introduction of exact perspective (since the 1420s), oil colors (around the 1470s), the sfumato (with Leonardo)" Image
Read 9 tweets
Jul 2
Prehistoric Uralic speakers were on the eastern edge of Siberia. They met Indo-Iranian speakers moving east, received some genetic admixture, adopted horses and bronze metallurgy, and then journeyed to the west to conquer Finland. Image
Image
"Yakutia_LNBA is associated with migrations of prehistoric Uralic speakers. We show that Yakutia_LNBA first dispersed westwards...into West Siberian communities associated with Seima-Turbino metallurgy....Seima-Turbino period individuals were diverse in their ancestry, also harbouring DNA from Indo-Iranian-associated pastoralists...Thus, both cultural transmission and migration were key to the Seima-Turbino phenomenon, which was involved in the initial spread of early Uralic-speaking communities."Image
"Ancient DNA reveals the prehistory of the Uralic and Yeniseian peoples"
nature.com/articles/s4158…
Read 5 tweets
Jul 2
88 papyrus documents mention the size of the cargo of ships entering Ptolemaic Egypt.
A general increase can be seen over time, such that by the mid-2nd century BC, the average size of the cargo of 37 ships entering the port of Alexandria was 179 tons!

This general increase in the size of ships and the capacity of ports is largely due to the achievements of Hellenistic Greek engineers in shipbuilding and port construction, one example of which is the Mega-Ship of Ptolemy IV Philopator, which had an unprecedented 4000 rowers and required the construction of a dry dock for its launch (c. 200 BC) which could be flooded by opening it to the sea and drained by "means of engines (organois)" after the ship returned to it.Image
Plutarch's description of the 'Tessarakonteres', the 4000 rowers. Image
Read 6 tweets
Jun 6
Historic European marriage and household types from data on 11 million individuals in 256 regions from 1700 to 1927.
"Female SMAM" - Average age of Marriage for Women.
"Female Service" - % of unmarried women working as servants among unmarried women.
"Marriage-Headship difference" - is the avg number of years since marriage to becoming head of a household.
"Proportion of Nuclear families" - looks at the Proportion of single-family households.Image
Date can be represented as two clusters, an Eastern and Western pattern of Marriage Image
In the West, Women marry late, and they go into the labor force beforehand. Married people form a new household headed by the Groom.
In the East, Women marry early so they don't go to work as servants. Married people become part of an existing household, where the Groom waits to become the new head.Image
Read 8 tweets
May 27
Religious Affiliations of American elites in subsequent editions of "Who's Who in America", a biographical dictionary of notable Americans. Image
Image
From this study:
"The Religious Affiliations of American Elites, 1930S to 1990S: A Note on the Pace of Disestablishment"
tandfonline.com/doi/abs/10.108…
Read 4 tweets
May 25
Highlighted threads from last month (April).
The Roman march into Saxony
The Roman conquest of Czechoslovakia. Almost.
Read 21 tweets

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