Projects
THE EAST PIER ANALEMMATIC SUNDIAL
Sundial Completed August 2006
August 2006 Looking Northwards
26.90 KB
August 2006 Looking South
33.99 KB
Sundial layout
28.13 KB
The equation of time
50.53 KB
The instruction plate
52.34 KB
The months of the year
70.44 KB
The OMD Stone
46.12 KB
The Analemmatic or human sundial differs from ordinary sundials in three respects:
- It is elliptic in shape, rather than circular
- It has hour points, as distinct from hour lines, to indicate the time of day
- It does not have a fixed metal or masonry gnomon for the purpose of throwing the all important shadow
This function of providing the shadow is carried out by the observer, who stands erect with his or her feet astride the centre line of the Calendar scale, on the appropriate date of the month, and reads the time by the sun as indicated by the direction of his or her shadow
The Sun Time, thus found, can be converted to Irish Standard Time by following the instructions given on the adjoining bronze plates. It will be seen from these instructions that, in making the time conversion, the following factors will be allowed for:
- The Equation of Time, which compensates for the irregular speed of the earth around the Sun, is laid out in graph form and its seasonal value in minutes will have to be added to, or subtracted from, the Sun Time according to the time of year, as indicated
- The Difference in Longitude between Greenwich and Dun Laoghaire, which is equivalent to 25 minutes in time and is always added to the Sun Time
- The addition of one hour to the Sun Time reading when Summer Time is in force
Historically the construction and use of early sundials go back to the dawn of civilisation. In fact they were Mankind's very first scientific instruments, predating even the invention of the wheel.
In an educational context, understanding the performance of a sundial will further the knowledge of the measurement of time and simplifies a basic apprehension of the Solar System.
The East Pier sundial was commissioned by the Dun Laoghaire Harbour Company as a feature of artistic and scientific interest for all who use the amenities of the Harbour, and to mark the successful restoration of the East Pier
Sundial Installation July 2006
July 2006 Looking North
67.59 KB
July 2006 The East Side View
39.66 KB
July 2006 The West Side View
33.90 KB
July 2006 The OMD Stone
51.67 KB
- Architectural Consultants: Shaffrey Associates
- Solar Calculations: Captain O M Deignan
- Graphic Design: Brian O'Connor
- Bronze Castings: CAST Ltd
- Masonry Work: Bobby Blount
Sundial Delivered
Sundial description
125.31 Kb
Descriptive plate monthly standing points
106.51 Kb
Equation of time
102.19 Kb
Sundial mid shot view point
88.36 Kb
Sundial unpacked
85.38 Kb
Sundial Setting Out July 2005
Sundial view 1
47.59 KB
Sundial Analemmatic simpistic diagram
17.24 KB
sundial view 4
42.80 KB
Table of Contents
