In the Census summaries 1851-1911, Templenoe CP contains entries in its list of Townlands something like Table 1a:

Table 1a: islands, from Census summaries


Table 1b: non-individuated island areas, from Table 1a

The Griffith Valuation lists all the islands in this portion of the CP. Immediately it becomes clear that there is a problem: the Valuation lists 58 islands - if the "Fifty-five others" are subtracted from 58, that leaves just 3. So it seems that the Greenane Islands are counted amongst the "Fifty-five others"; but clearly the area of the Greenane Islands is not included in the area of the "Fifty-five others".

The Valuation individuates each island by an identifying-number (No1 to No58). And luckily there exists an OS 6-inch map showing the area of each island, and marked up with (most of) these identifying-numbers. These two source-documents neatly confirm each other, island-count and island-areas match; but the island-areas do not match the Census summary:

Total area of 58 islands, Templenoe CP, Dunkerron South barony

1851-91
Census summaries,	110	3	29
OS & Valuation,	110	3	25

IreGaz prefers the OS/Valuation island-area, since this figure was the source-data for the Census summaries.

The name "Greenane Islands" is printed on OS maps amongst a large group of islands: could IreGaz identify islands with the required total area: 24 0 34? There is a mathematical algorithm which, given a set of numbers, can list all possible subsets which add up to a required total. It would be foolish to ask a computer to use this algorithm on all 58 islands identified in the Valuation, as there would probably be a long list of suitably-summing subsets. But a sensible selection of likely islands in the named area, plus a generous serving of luck, enabled IreGaz to discover a group of 17 islands totalling 24 0 34. A crosscheck with Valuation data showed that all 17 islands were recorded in the name of one owner; so it is likely that IreGaz has identified something very close to the correct subset of islands.

IreGaz now had to allocate all 58 islands to EDs. From the 1901 Census summary it was clear that islands were recorded in 4 EDs of Templenoe CP: Dromore ED, Greenane ED, Kenmare ED and Reen ED; and it seemed that it should be comparatively easy to allocate (a) 4 islands to Dromore ED, and (b) 10 islands to Kenmare ED (only 2 of its townlands fell within Templenoe CP, Dunkerron South barony). After several iterations (consulting the Valuation, and OS maps of various periods), islands were allocated as follows:

Table 2a: islands from OS, Valuation, & Census summaries

Table 2b: small-island area-totals from Table 2a