The Tree,
analemmatic anthropic sundial.

The analemmatic sundial is probably one of the most intriguing sundials. It is hard to resist to the temptation of standing over the sundial, becoming a gnomon and showing the hour with our own shadow, above all laymen undergo its fascination: just a glance, apparently careless, and one find himself on the footboard to watch what is happening. I think the analemmatic is the most propaedeutic among sundials for its entertainment feature but its working isn't so easy to be understood.
The analemmatic sundial isn't suitable for the civil time because it is no possible to correct the time with the Equation of Time (it is not possible but for the noon), so it has a double impact: on one hand it catches our attention and tempts us to test it, on the other hand it puzzles us because it shows a time which is different from the watch one; for these reasons I believe it is an entertainment and a didactic instrument, just because it spurs the curious people wondering about time systems.
Since it is an entertainment sundial and it is right for local time, the analemmatic sundial became a project of the Gnomonics Course at the Third Age University (UTE Università della Terza Età); the project was to realize an anelammatic sundial in the parc of the sporting centre which is very popular among the citizens of Paderno Dugnano (MI). The parc has sporting facilities and outdoor games, it is very popular for those who play sports or simply enjoy being in the open air. For these reasons we are convinced the guests of the parc may appreciate to forget the time of their watches and turn their attention to the 'time' of the parc which is attuned to the cycle of nature and to the Sun, that is the local time. In reality nature has not choosed to be measured with this time system, but this time is synchronized with the local noon and not with the noon of the meridian of the fuse, that is the noon of another place. This idea has been expressed by the shape of the sundial: the footboard has the outline of the trunk of a tree and the hour indexes have the outline of the leaves of our parc. The analemmatic sundial is on costruction now and it will be installed next autumn (2003).

 
The place
Near the entrance of the parc there are the municipal swimming-pool and the sporting center, both of them are in front of a pedestrian way: via Coppi.
  
The sundial
The beginning of via Coppi is bound to a meadow strip which well fits for the sundial, where there are no natural or architectural obstacles to get lighting. Here the sundial may work all the year from 6 to 18, the strip meadow is sheltered but there is a good visibility and it is easily reachable from those who are in the parc. The leaves and the footboard are made by a unalterable plastic material which can stand all weather conditions, they are placed closed to the ground and hooked to a buried metal frame. The course of Gnomonics has the task to find the meridian line and to help installing the frame, obviously the 'student' attends to the calculations about sundial and follows its realization. The sundial will indicate the true time of Paderno Dugnano and a signboard near the sundial will explain how to get the civil time and will give other informations about the sundial. Aside the pictures show a photomontage of the analemmatic sundial placed in the meadow, its size will be about 5 x 3 meters (15 x 9 feet).
The leaves
The botanic species are:
horse-chestnut (VI), hazel (VII), elm (VIII), oak (IX), maple (X), maple (XI), tulip tree(XII), lime tree (XIII), oak (XIV), cherry tree(XV), liquidambar (XVI), oak (XVII), beech (XVIII).
       
 
Download
Excel sheet to calculate the positions of the indexes of an horizontal analemmatic sundial at any latitude.
It possible to work with local or time zone hours.
The file xls (20k) is compressed in
a file zip (5k).
analemmatico.xls in formato analemmatico.zip
English version
 

Some didactic notes for those who approach gnomonics

... on costruction