Description: 

Explanation of map and interactions
The map attempts to illustrate two features of the defence of Killiney Bay between 1797 and 1813:

• the results of the initial survey in 1797 by Major La Chaussée which identified three areas of coastal weakness and three broad characterisations of the inland terrain. Troops from the Camp could be mobilised to both defend the coastal weaknesses and deal with such invaders as penetrated these and reached the inland sections. As it turned out, the troops' role in this period was a broader inland one in the context of the 1798 Rebellion. The Rebellion made the authorities very nervous of a camp of mainly Catholic militia on the outskirts of the city. This, and the receding threat of invasion, led to the winding up of the Camp in early 1799. Even though war broke out again in 1803 the Camp was not reconstituted. Rather the response was to erect the permanent defences described below.
• permanent defences erected by the authorities 1803-1804 to copperfasten the defence of the Bay after the further outbreak of war. These consisted of a series of Martello Towers and Batteries which can be clearly seen to be concentrated on the points of coastal weakness identified by La Chaussée. No. 4 Tower, while not at a point of coastal weakness seems to have been there, in part at least, to maintain overlapping fire. Between them, these defences gave a continuous ribbon of protection extending about one mile out from the coastline.

Manipulating the Map
The following features can be overlaid on the map, cleared and then recombined, in any combination to suit the viewer. A particularly interesting combination is the three coastal weaknesses and the subsequent towers and batteries.

As far as the towers and batteries are concerned, hovering over them will produce an identifier in the panel at the top of the map. Clicking on them will provide further information and hotlinks where appropriate. [I am still trying to introduce the same facility on the other features but my knowledge of Javascript has not yet reached that exalted level! For the moment, the panel will show a once-off description as the item is invoked.]

The Loughlinstown Camp shows the extent of the Camp and the connecting military road which led to the coast. This ran along the old Wyatville Rd. to Ballybrack cross roads and then along the present Military Road from there to the coast.

The Coastal Weaknesses and Inland Sections are those identified by La Chaussée and an extract from his report explaining their significance is set out below for convenience.

Finally, the Overlapping Fire clearly shows the extent of protection of the Bay introduced with the permanent defences after 1803. Note that without Tower No.4 overlapping fire would not be maintained. This is the only tower/battery (excepting Dalkey Island) whose position is not part of the defence of one of the identified coastal weaknesses.

La Chaussée's survey
The extracts below are translated from La Chaussée's report and set out his descriptions of both the coastal weaknesses and the inland sections.

1. The Coast The coastline is bordered by cliffs, varying in height from 20 to 70 feet, except in three places: between the bottom of the Obelisk Mountain (Killiney Hill) and the Lime Kiln - a distance of 300 yards. at the mouth of the stream which runs across the brow of the camp (Shanganagh River) – a distance of 400 yards. at the mouth of the Dargle – a distance of 600 yards – and from there to the mountain of Bray Head. As well as these three places there are other small breaks in the cliffs caused by little streams or made by local residents for the convenience of access to the beach. 2. Inland The hinterland of the bay is shaped like an amphitheatre stretching back to the hills, but three major divisions can be identified: from the Obelisk Mountain to the wood at Fair View (a distance of 2 ½ miles). This section forms a large basin, about one mile wide at its lowest point. There are no natural barriers in this section to impede the progress of the enemy should he succeed in penetrating the coastal defences. from Fair View wood to Bray village (a distance of 1½ miles). This section is made up entirely of two fairly regular slopes the summit of which is about 500-700 yards from the sea. The first of these slopes towards the sea in a very gently incline and the second a little steeper towards the Bray to Dublin highway. The coastal slope is fairly open, but the inland one is broken by a considerable number of ditches, slopes, streams etc., all of which make communication and access very difficult. from bray village to the foot of the mountain called bray Head (a distance of ¾ mile). This section is fairly regular; the coast is low on the seaward side and it rises in the form of a crater, the centre of which is occupied by a fairly large castle, surrounded by trees and walls.