Going through the names of the individuals who sat on the Grand Jury for the County of Londonderry from the year 1820, (that was the first year that there were two Assizes in each year, Spring and Summer), I noticed that the word, "Colt," was written against the names of certain gentlemen. On purusing this matter further it seems that this term was used to identify persons who were appearing on the Jury for the first time. At the Spring Assizes of 1874 where the Judges were Mr Baron Fitzgerald and Chief Justice Whiteside no fewer than five of the twenty three jurors were, "Colts," namely Professor Richard Smyth MP, Daniel Taylor Esq MP, and Messrs. William McCarter, John Haslett and James Clark.
Grand Juries were done away with by virtue of the Grand Jury (Abolition) Act (Northern Ireland) 1969. Their administrative powers in connection with such things as roads, bridges and asylums had been previously taken away by the Local Government (Ireland) Act 1898. This same Act established the cities of Belfast and Londonderry as separate County Boroughs.
The foremen of the Grand Jury for County Londonderry from 1820 until the end of the nineteenth century and the dates of their appointment were as follows:-
Alexander Robert Stewart MP 1820
Henry Barre Beresford 1821
Rt. Hon. Sir George Fitzgerald Hill 1821
Andrew Knox 1822
Sir James Bruce 1823
Geo. Robert Dawson MP
Marcus McCausland 1827
Sir Robert Bateson MP 1834
Connolly Gage 1842
Henry Richardson 1845
Thomas Bateson 1846
Sir H Harvey Bruce 1849
Thomas Scott 1851
Theobald James MP 1852
James Johnston Clark MP 1858
Robert Peel Dawson MP 1860
Acheson Lyle 1862
Sir Frederick Wm. Heygate 1867
John B Beresford 1869
R. A. Ogilby DL 1889