Gas lighting was introduced across Dublin in 1825 [i] two years after it had been adopted in Belfast [ii]. When the hero says "from Belfast to Dublin…I came" he is presumably referring only to his journey.

References:
[i] Meehan, Patrick Dublin Historical Record Vol. 5, No. 4 (Jun. - Aug., 1943), p135
[ii] Culture Northern Ireland website https://www.culturenorthernireland.org/features/heritage/belfast-gasworks (accessed 11Feb21)

Walter Hancock's road going steam coach 'Erin' was in Dublin in January 1835. Hancock recorded the event as follows : -
About the end of November the writer was induced, at the particular request of some influential parties, to make arrangements for the conveyance of one of his carriages to Dublin, and in consequence discontinued running on the Paddington road. The Era" was the carriage chosen for the trip, and preparatory thereto, its outward embellishments were altered, and its name changed in compliment to the country of its temporary destination, from " Era" to " Erin." It was shipped on board the "Thames" steam-vessel on the 30th of December, 1834, and arrived safely in Dublin on the 6th of January, 1835.

On being landed, the writer commenced running it on the Howth road, and through all the principal streets, and most frequented thoroughfares of the city of Dublin. As this was the first steam-carriage that ever plied upon any common road in Ireland, its appearance naturally attracted an immense concourse of spectators; all of whom, as well as those who rode in the carriage, and the public prints of the City, bore ample and gratifying testimony to the efficiency of its performances. Stewart's Dispatch of the 19th of January gives the following account of its running

"HIBERNIAN STEAM-COACH COMPANY.

Since the experimental locomotive carriage, the "Erin" has commenced running through town, we have invariably had bad weather, with the exception of yesterday ; it does not, however, seem to have had the least effect on the carriage hail, rain, or snow, has not prevented the "Erin" steaming through every part of the City daily. The directors, very prudently, never gave any previous notice of their route, or the hour ; still the crowds were tremendous. The 'Erin' on Saturday, left the station-house at Clontarf with a large party of ladies and gentlemen, at one o'clock, going by Balllybough and Annesley bridges, through Abbey-street, Sackville-street, Westmorland-street, Grafton-street" Nassau-street, and Dawson-street, to Stephen's-green, round which it went three times, at the rate of eighteen miles an hour it then returned to the station-house in Great Brunswick-street, where having taken in a supply of water, it proceeded to Sackville-street at the time crowded with vehicles of every description"

Reference: Hancock, Walter - Narrative of twelve years' experiments, (1824-1836) demonstrative of the practica-bility and advantage of employing steam-carriages on common roads. (London, John Wheale, Architectural Li-brary, 1838) pp 66-67

An allusion to a statement attributed by the Bible to King Solomon - Ecclesiastes 1:4-11, "there is nothing new under the sun"

The steam powered coffee grinder seems to have been a reality. A poem (Bar540~The Steam-Engine Coffee Grinder) by Joseph Hodgeson born in Rishton, Lancashire circa 1783 begins "He grinds his coffee now with steam, / To shew the world how he can scheme,"