Industrial Past 4

Seven Sisters Minim 1

We were walking beside the Swan River in Minim Cove, Perth this week and stopped to look at these quirky chairs. There are seven of them and they are called the Seven Sisters – not referring to the star constellation of that name, but to the fact that there used to be seven hills in this area.

Today there is just one of the hills left; Buckland Hill. The others were all quarried in the late 19th and early 20th centuries for limestone, which was used to construct buildings and roads in Perth.

Seven Sisters Minim 2


Roman Time 3

Santa Maria Angeli 5

The amazing thing about the sundial in the church of Santa Maria degli Angeli et dei Martiri in Rome, which we described yesterday, is that you can actually see it in operation.

If you go to the church around midday (the exact timing varies through the year), a spot of sunlight shines through a small hole in the wall on the south side of the church, shown above. The light shines onto the floor, showing the elevation of the sun on the day. That information enables astronomers to work out the date and the timing of equinoxes and solstices. One obvious suggestion: go there on a sunny day.

Santa Maria Angeli 6

Roman Time 2

Santa Maria Angeli 3

Yesterday we only told part of the story about the amazing sundial in the church of Santa Maria degli Angeli et dei Martiri in Rome. There are actually two sundials set into the floor of the church, not one.

There is a long brass strip (above) which allows observers to work out the dates of equinoxes and solstices, as the sun moves relative to the earth through the year. That information is needed for making accurate calendars and also to establish the correct dates for Easter.

The second sundial tracks the movement of the Pole Star – a more distant sun – through the year, shown in a series of ellipses on the floor (below). There is plenty of interesting science in this church!

Santa Maria Angeli 4


Roman Time

Santa Maria Angeli 1

We saw many interesting time-related objects during our visit to Rome earlier this month. Maybe the most spectacular was in the church of Santa Maria degli Angeli et dei Martiri, which we mentioned yesterday.

The church is very interesting its own right, since it was built by Michelangelo Buonarotti in 1563-4, right inside the Roman Baths of Diocletian. But even more interesting is the fact that a huge sundial was constructed in the floor of the church by the Italian astronomer Francesco Bianchini in 1702.

Santa Maria Angeli 2

Roamin’ Ram

Aries Santa Maria Angeli

We saw this sheep in the floor of the church of Santa Maria degli Angeli et dei Martiri (Saint Mary of the Angels and Martyrs) in Rome recently. It is actually Aries, the Ram in the western zodiac. The other zodiac signs are also represented, including Libra (below). These zodiac signs are part of something even bigger and more interesting … more about that tomorrow.

Aries Santa Maria Angeli

Roamin’ Sheep 1

Cosma Damiano Rome 1We saw a number of sheep (and goats) during our visit to Rome over the past few weeks. They had nothing to do with Chinese New Year, but felt rather apt since this is now the Year of the Sheep.

The ones above are in the 6th and 7th century mosaics at the easily overlooked Basilica of Saints Cosma and Damiano. The small church is tucked in beside the Roman Forum and doesn’t look like much from the outside. But it incorporates the ancient Temple of Romulus and also has a large Christmas crib scene which is on display all year round (more about that in December).

Cosma Damiano Rome  2