OSI online maps new version

kildarejohn

Apologies if this is old news to some. The online map facility at www.osi.ie was upgraded a few months ago, I only recently looked into the new features. The maps are now found on a link to Geohive. Several new features of historical interest -

• Historical maps - you can now display 2 or three of the historical maps overlaying each other and fade in or out each one, so you can compare very accurately present version v. 1900 25" map and 1840's 6" map
• There is a new Historical map layer which is called "Cassini" (for some obscure reason), this is 6" map from c. 1930's, so this adds interesting information on changes between the 1900 map and the current map
• Under the Environemnt tab there are options to display maps with National Monument locations, and also National Inventory of Architectural Heritage building locations. NM's also include descriptive text
• Under the Population tab there is 1901 census townland data, but only for Donegal

So overall lots of interesting stuff to explore. Anyone found anything else of interest on this site?

tac foley

Giovanni Domenico Cassini (8 June 1625 – 14 September 1712) was an Italian mathematician, astronomer, astrologer and engineer. Cassini was born in Perinaldo, near Imperia, at that time in the County of Nice, part of the Duchy of Savoy. Cassini is known for his work in the fields of astronomy and engineering. Cassini discovered four satellites of the planet Saturn and noted the division of the rings of Saturn; the Cassini Division was named after him. Giovanni Domenico Cassini was also the first of his family to begin work on the project of creating a topographic map of France.

The Cassini spaceprobe, launched in 1997, was named after him and became the fourth to visit Saturn and the first to orbit the planet.

The mapping is named in his honour.

tac

The Chieftain

tac foley wrote: »

Giovanni Domenico Cassini (8 June 1625 – 14 September 1712) was an Italian mathematician, astronomer, astrologer and engineer. Cassini was born in Perinaldo, near Imperia, at that time in the County of Nice, part of the Duchy of Savoy. Cassini is known for his work in the fields of astronomy and engineering. Cassini discovered four satellites of the planet Saturn and noted the division of the rings of Saturn; the Cassini Division was named after him. Giovanni Domenico Cassini was also the first of his family to begin work on the project of creating a topographic map of France.

The Cassini spaceprobe, launched in 1997, was named after him and became the fourth to visit Saturn and the first to orbit the planet.

The mapping is named in his honour.

tac

Yes, Cassini is well known in scientific circles. But the question remains - why was this particular Irish survey named in his honor?

tabbey

The Chieftain wrote: »

Yes, Cassini is well known in scientific circles. But the question remains - why was this particular Irish survey named in his honor?

Would it by any chance have anything to do with DeValera being a fan?

He was certainly an enthusiast of maths & physics.

Duckworth_Luas

The Cassini map series consisted of a separate 6 inches to 1 mile scale mappping for each county, with each one using the Cassini projection.

This projection suited the general shape of Irish counties which is wide in a north-south direction, but narrow east-west (Roscommon, Tipperary, Kilkenny, Donegal, Leitrim, Dublin etc).

A disadvantage of the series was that the borders of neighbouring counties would not match due to distortions caused by the projection used.

Nowadays, mapping is carried out on an all island basis using the Transverse Mercator projection.

The peculiarities of the series led to it being called Cassini for short, nothing else.