It appears that Grubb’s first employment was as an office clerk in Dublin. But, from this role he moved decisively towards an interest in engineering and specifically innovative instrument manufacture and,
“for much of his life Thomas’s efforts were directed towards, and most of his income was derived from, his appointment as Engineer to the Bank of Ireland. In this capacity his ingenious inventions were responsible for substantial improvements in the engraving, printing and numbering of banknotes.”
He was appointed to his post in the Bank of Ireland in 1840, was commissioned by Trinity College Dublin to create precision instruments and also manufactured twenty sets of magnetometers for a global network of magnetic observatories.
He was interested in a variety of different optical instruments. He designed and manufactured camera lenses, which he patented. The most significant of which was created in 1858 when he designed a portable wet plate camera of an unusual composition comprising a collapsible framework of rods. Though Grubb’s design was impressive it never made it into production. This was at a period when the smallest camera needed to be placed in a small suitcase for transportation. Significantly, the oldest known stereoscopic material in Ireland can be attributed to Thomas Grubb. While his early work involved the production of printing and other machinery he developed a keen interest in astronomy and made his own observatory and small reflector telescope.
By the time of Griffiths Valuations Thomas had become an affluent property holder with buildings and lands at Leinster Terrace Harroldscross, Ontario Terrace Ranelagh and the adjacent Charlemont Street Upper. The total valuation on these properties was an enormous £120 16s & 0d. In fact, he was also in a position to sub-let a portion of his Charlemont Property to a Robert Rothwell. It appears that one of the many products produced by Grubb at the Charlemont property was cast-iron billiard tables.
“The 19th Century has often been referred to as the golden age of astronomy in Ireland. It was a period of great innovation in telescope design and in astronomical discovery, in which Irish scientists played a leading role, and one quite disproportionate to the size of the Irish scientific community.”
The Grubbs were a renowned Tipperary Quaker family. The founding father of the family was John [1682-1731] who married Anne Williams [1689-1765]. They had 10 children including William [1719-1774]. William, the third son, worked as a farmer and married Margaret, daughter of John Boles of Woodhouse, Fethard. They had 14 children including William. He married Elizabeth Taylor with whom he had six children and following her death in 1787 he married Eleanor Fayle of Dublin in 1791. He had three children by his second marriage including Thomas who was born on the 4th of February 1800 in Waterford. Whether the family had moved to Waterford or were resident temporarily in the area at that time is unknown at present.
Thomas married Sarah Palmer [she died in 1883] in 1826 and “had nine children; five sons and four daughters (of whom three died young).” Thomas in later life suffered greatly from rheumatism and other serious ailments.