Leonardo, lenses and the earliest photograph?

Posted on 28/05/2012 by dougaj4

Walking around Venice I had seen a large poster for a Leonardo Da Vinci exhibition, with no details of locations or dates, and on the Internet the only links were to exhibitions from previous years, but arriving in Florence I discovered that the exhibition was located at Via Cavour, 21, which just happened to be exactly the same address as the excellent hotel we were staying at.

Amongst the exhibits were devices making use of glass lenses:

Leonardo’s Lantern

and a device for accurate drawing of perspective:

Perspective Drawing Device

Model of perspective drawing device

These machines show the fascination of Da Vinci with the use and properties of light, and the production of anatomically perfect images of the human body, which supports the hypothesis that he was responsible for the famous Shroud of Turin.  It is suggested that this image is in fact of Leonardo’s own face, and is the first photographic image.  Further evidence is provided in this You Tube video:

Of course, not everybody agrees.  This link: Leonardo Da Vinci and the Shroud of Turin provides a somewhat selective skepticism about the Leonardo hypothesis, suggesting instead:

The most popular theory is the “scorch” or “thermonuclear radiation” theory. Advocates of this idea suggest that the intense light and heat generated by Christ’s body at the moment of resurrection might have burned his image into the cloth, much as “permanent shadows” of men in Hiroshima were burned into walls and other surfaces by the atomic explosion in 1945.

OK, I’m convinced.

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Campaniles, Earthquakes and Photoshop

Posted on 25/05/2012 by dougaj4

The Campanile in St Mark’s Square in Venice is the only non-original structure in the square, the original having collapsed in 1902, but the new structure is a faithful replica of the original, and still provides fine views of the city:

St. Mark’s Campanile, Venice

View from the top

St Mark’s Square from the Campanile

I asked our tour leader if the cause of the collapse of the Campanile had been an earthquake.  No she replied, Venice is not subject to Earthquake activity.  That very night we were woken at 4:00 a.m. by vigorous shaking of our hotel rooms, due to a magnitude 6.1 earthquake north of Bologna.  Well she never claimed to be a seismologist.

In fact the actual direct cause of the actual collapse does not seem to have been an earthquake, although earthquake activity may well have contributed to the weakening of the structure over the years.  Searching the internet the best report I could find of the event came from, of all places, The West Gippsland Gazette of 23 Sep 1902, which may be viewed here:

http://trove.nla.gov.au/ndp/del/article/68721171

Extract from the West Gippsland Gazzette report

Amongst the photographs of the collapse are many genuine shots of the resulting debris:

Collapsed campanile

but also many images claiming to show the actual collapse.  In fact these can easily be seen to have been manipulated photographs, and the technology of the time would not have allowed a sharp rendition of this sort of action shot, even in the unlikely event of a camera being pointed in just the right direction at the time.

Fake photograph of the collapse

I thought this was likely to have been the earliest example of a photograph being “Phot0-shopped”, but there is another Italian example from hundreds of years earlier which may well have that honour, and that will be the subject of my next report.

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More Ligurian Arches

Posted on 22/05/2012 by dougaj4

We will complete the stay in Camoglia with another collection of arch structures (great and small, old and new) from the district:

Santuario di Montallegro, near Rapallo

Santuario di Montallegro

Monastry of San Fruttuoso

Monastry of San Fruttuoso

Monastry of San Fruttuoso

Monastry of San Fruttuoso

Monastry of San Fruttuoso

Monastry of San Fruttuoso

Rail viaduct at Recco

Rail viaduct at Recco, at time of construction

The recent photo of the Recco Rail Viaduct is from the Structurae Database.

The photo from the time of construction is from: http://www.miol.it/stagniweb/fs101.htm

The Recco Viaduct (line Genoa-La Spezia) was rebuilt in 1946-48 with 6 parabolic arches on a curve of 400 m radius. Thanks to its design qualities and to the importance of the railway line, it can be assumed as one of the symbols of the reconstruction.

 

 

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They all laughed at Christopher Columbus …

Posted on 16/05/2012 by dougaj4

…When he said the World was round (or rather, they didn’t).

Christopher Columbus was born in the town of Genova, in what is now North-West Italy.  The adjacent towns are happy to share the credit:

Christopher Columbus at Santa Margherita

Christopher Columbus as Rapallo

It is (or at least was) a popular myth that the accepted wisdom at the time was that the Earth was flat, until Columbus sailed west with the intention of reaching China, and bumped into the American continent on the way.  In fact the Greeks had believed the Earth to be roughly spherical about 2000 years earlier, and had made an estimate of the Earth’s radius, based on the length of mid-day shadows at different latitudes.  This knowledge had been preserved, and would have been well known to educated people of the era of Columbus (see Wikipedia’s Spherical Earth article for more details).

How widespread this knowledge was amongst the general populace is open to debate, but there is at least some evidence that it was known outside the world of the literate.  for instance from the Wikipedia article:

the Elucidarium of Honorius Augustodunensis (c. 1120), an important manual for the instruction of lesser clergy, which was translated into Middle English, Old French, Middle High German, Old Russian, Middle Dutch, Old Norse, Icelandic, Spanish, and several Italian dialects, explicitly refers to a spherical Earth. Likewise, the fact that Bertold von Regensburg (mid-13th century) used the spherical Earth as a sermonic illustration shows that he could assume this knowledge among his congregation. The sermon was held in the vernacular German, and thus was not intended for a learned audience.

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Ligurian Arches

Posted on 15/05/2012 by dougaj4

We have looked previously at Robert Hooke’s statement on the mathematical analysis of arches:

 abcccddeeeeefggiiiiiiiillmmmmnnnnnooprrsssttttttuuuuuuuvx

but of course  people had been constructing large arch structures for many hundreds of years before Hooke made his enigmatic statement, and the masters, if not the inventors, of the arch were the Romans.  In future posts I will be looking at some of the historically important arch bridges in Northern Italy, but for today, here is a collection of arches (natural and constructed) from a walk in the Cinque Terre National Park, and in and around Camogli:

Arch near the harbour at Manarola

The Harbour at Vernazza

The Harbour at Vernazza

The Harbour at Vernazza

The Harbour at Vernazza, Natural Arches

The Harbour as Vernazza

Natural and Railway arches near Vernazza

Camogli Station

Arched strata at Salita Mandrella a Monte
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