The Wild Boar of Ben Bulben

CHOOSING A THEME

The image on the right is the crest of Sligo County Council which was adopted in 1980. The design on the black shield, which shows an open book on which there is a Celtic Cross and a red rose, represents collectively the literary and cultural history of Sligo. These refer to such early works as the Books of Ballymote and Lecan, while the rose was a significant theme in the poetry of W. B. Yeats. The escallop shells sprinkled on the shield refer to the origin of the word Sligeach -- "a place abounding in shells". The boar's head refers to the "wild boar of Ben Bulben" in the Diarmuid and Gráinne myth. The colour scheme of the crest incorporates the Sligo GAA colours of black and white.

Motto: "Land of Heart's Desire" comes from the title of a play by W. B. Yeats, which has a local setting.

Crest of Sligo County Council

DIARMUID AND GRÁINNE IN SLIGO

(Extract from the legend of Diarmuid and Gráinne)

Gráinne, daughter of King Cormac, elopes with Diarmuid rather than marry the ageing Fionn Mac Cumhail, and Fionn has murderous thoughts on his mind as he chases the couple around Ireland. Diarmuid and Gráinne camp in the Wood of Duross in West Sligo and they are safe for some time. There is a fearsome creature in the wood, Sharvan the Surly Giant, who is guarding the magic quicken tree with its magic red berries. Anyone who ate three of these berries would have their youth restored. Because Gráinne wanted to stay young always, she had to have some. Diarmuid asks Sharvan for some berries but is refused. He has to fight Sharvan, he wins, and takes over Sharvan's hut. The couple have many happy days and nights in the Wood of Duross until forced off again by Fionn and his followers. Finally, they arrive at the fort of Gráinne's father, King Cormac, son of Art, at Keash, Co. Sligo. They build a home for themselves, Rath-Gráinne, and raise four sons and one daughter. After many years, Gráinne invites her father and Fionn Mac Cumhaill to a great feast which lasts a whole year, and there is great merriment during that time.

At the end of the year, after all have gone to bed one night, Diarmuid hears the baying of a hound and goes to Ben Bulben to find it. Fionn is there before him, and tells him the hound has found the scent of the magical Wild Boar of Ben Bulben. Diarmuid is soon alone facing this charging animal. Diarmuid’s sword is broken in the charge, and in desperation he flings its hilt into the head of the wild creature as it passes by. The boar is killed, and but not before Diarmuid is mortally wounded by a thrust of the animal’s tusks.

Carriers for figures of Diarmuid and Gráinne as they do a celebratory boogie outside Sharvan's hut in the Wood of Duross, Sligo

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Sculpture of Diarmuid and Gráinne by Cillian Rogers, at Ballisadare, Co. Sligo

(Click image to enlarge)

The models above were built as general carriers for characters and are used for training in the use of the Cricket software. The two motors in each model are independently controlled by Crickets (from http://handyboard.com) which comes with a Logo-style interface. Example: a, onfor 10 turns on motor A for ten tenths of a second and ab, onfor 20 turns on both motors for two seconds. Use: wait 10 to get a one second time delay, and rd to get the models to reverse direction. A program is written as one or more procedures and downloaded via an infrared interface to the Cricket. A procedure always starts with to and finishes with end. Note how close to human communication it is: "Pat, turn off the telly for a second."

Another programming language called LogoBlocks is also available. This uses icons which can be dragged into place to build the program.

Sensors (e.g. light, touch and temperature) and display panels are also available for Crickets, and the small Cricket size and price are huge advantages. Much work has been done on models using Crickets at the Digital Hub, Thomas St., Dublin.

(Note: Coloured markers can be placed through the holes in the wooden deck on the larger model above so that it can be used for creative artwork.)

WHAT WE WANT TO BUILD

We will need two moving models, one for the boar and one for the hound. Both can have the same mechanical construction as they will represent moving animals, but will wear different costumes. We also want to choose a suitable setting.

THE MECHANICS

We can build a model on a chassis of beams with the RCX on top. The motors A and C are to be controlled independently to get left and right movement as well as forward and backward. Motor B is used for jaw action. The castor at the rear will help support the module. We can attach a light sensor beside the wheel on one side to guide the model along a black line so that one can chase the other along the same path. The model also responds to the hand-held remote control which is very useful for testing. When the model on the right was being shown at the RDS, visitors were asked to place a one cent coin in the boar's mouth and watch if its mouth closed as it took it to its owner!

(Note: The model on the right is not designed or built to a plan, but rather parts were added as the idea developed. The philosophy behind the Mindstorms theme is that each model starts with an idea in a pupil's head, and the designing/redesigning and building/rebuilding process is much more important than the product. Children will naturally try to improve designs by themselves, through trying out new ideas or by observing models built by other groups.)

The Wild Boar of Ben Bulben

(Click image to zoom)