Elijah Hart advertises his daguerreotype portraits in Sydney in 1852, where he ‘…engages to furnish none but pleasing and faithful likenesses.’  A rather lengthy article the following year provides an informative outline of photographic processes, also advising that Mr. Hart is to close his Sydney studio and proceed on a tour ‘of the interior. ’  [access full article]
By the end of May, 1854, Hart had arrived at Maitland advertising as a Daguerrean artist, available at the Northumberland Hotel. 
More elaborate advertising appears in June: 
Hart's Daguerreotype Portrait Gallery. E. HART, in announcing his arrival at the
Northumberland Hotel, West Maitland, begs respectfully to invite public attention
to the SPLENDID MINIATURES he is now taking in Daguerreotype or by the new
Xylo-graphic or Glass Process. These pictures are tree from any metallic reflection,
may be seen in any position through the glass on which they are taken, and every
thing appears natural, and not reversed. They are indestructible by time, and
possess a richness of tone, exquisite softness, combined with the beautiful delineation,
equal if not superior to Daguerreotype.
A large Collection of Specimens by each process on view.
Stereoscopes with Diagrams and Views for sale, and portraits taken and colored in
the highest style of art for these marvellously amusing instruments.
From the short time E. H. requires a sitting for taking these charming pictures,
say from one to ten seconds, they are free from that constrained appearance usually observed.
Northumberland Hotel, West Maitland. Open from 9 till 4. June 3rd, 1854.
Hart’s advertising explains the ‘new discoveries' in photography, that is, the Xylographic or glass portrait.
THESE charming pictures are free from any metallic reflection, and may be seen under any aspect as easily as a print, and the Portraits being looked at through the glass on which they are taken, everything is natural and not reversed, as by the usual method. They are indestructible by time, and possess a richness of tone, exquisite softness, combined with beautiful delineation, equal if not superior to Daguerreotype. 
Throughout July and August 1854, Hart advertises that his stay in Maitland “will not be so long as originally intended”, having to return to Sydney to arrange business, prior to his intended visit to Patrick’s Plains, Newcastle and the surrounding districts. Hart’s Daguerrean Gallery at the Northumberland Hotel closes in October 1854. 
Hart relocates to Newcastle for November and then reappears back in Sydney for a number of months, but in June of 1855 Hart reopens in Maitland, resuming his profession in one of the cottages known as Early’s Terrace, while his new gallery is being built. 
Hart makes good use of “opinions of the press” in his advertising, noting his ‘magnificent apparatus’: 
"The productions of Mr Hart's magnificent apparatus are the most perfect of any we have seen in the colony."- Bell's Life, January.
There is an odd mix up with the name Miller in a Mercury advertisement of October 1855, which Hart quickly refutes and by this time Hart has relocated the studio to Devonshire Street. 
Only a few days later, Hart places an advertisement indicating his intention to ‘go into another profession’ hence a great reduction in prices. 
This change of profession apparently never occurred at this time, as Hart continues his photography business in Maitland, advertising in 1856 that portraits are taken in all branches of photography, viz. daguerreotype, callotype, xylography or glass pictures.  By January of 1857 Hart is located in High Street, using a lengthy advertisement [access full article], extolling the virtues of photography as an art form, the very perfection of apparatus used by Hart and suggestions for dress for both ladies and gentlemen to ensure the best image is obtained. 
It is in September 1857 when Hart's first flood photographs are reported. 
Hart placed several advertisements for the sale of cameras through February and March of 1858 which provide an accurate description of the equipment he had been using:
FOR SALE, a MAGNIFICENT WHOLE PLATE DAGUERREOTYPE APPARATUS,
complete. Price, with instructions, £45. Also, A QUARTER PLATE, complete, £35.
Either of the above would be a Fortune to any man visiting our Gold Fields.
Hart’s dainty collodiotypes are mentioned in the Maitland Mercury:
We were shown the other day a miniature portrait executed in collodiotype by Mr. E. Hart, of Maitland, and set in a small locket. The portrait was admirably distinct and sharp and we notice it as being considerably smaller than any collodiotype portrait we have ever seen though we have met daguerreotypes of similar dimensions. 
After advertising his intention to ‘shortly visit the country districts to take portraits’ (specifying Patricks’ Plains and Wollombi) the Hart’s property is described in a notice ‘to let’ : 
Those DESIRABLE BUSINESS PREMISES, next the Joint Stock Bank, known a
Hart's Portrait Gallery, containing 9 rooms, viz , Ground Floor shop, 18 x 30,
two parlours, suitable for offices, kitchen, fitted with oven, range, and bath
boiler; First floor - four bedrooms, 15 x 12, drawing-room, 16 x 21.
Large enclosed yard, with sheds, &c. , kitchen and flower garden.
The end of August sees Hart advertising the new milleniatypes - the latest improvement in portraiture, which are taken on leather or oil-cloth. Advantages are described as durability, not liable to fracture and can be bent without injury. 
A major change in Hart’s business affairs takes place in January of 1859, when he opens his “Maitland Auction Mart” at 'those central and spacious premises known as Hart's Portrait Gallery.' Sale stock comprised colonial produce, furniture and general merchandise, with Hart as Auctioneer and General Commission Agent, although he continues advertising for portrait production at the same time.
Through July and August of 1859 photographic competitor Roggenkamp is also advertising, so Hart again relies on an innovative photographic process, viz. alabastrine ambrotype, to stand out from the competition. 
In November of 1859, Hart states that he has taken 7,495 portraits,  and in December , “More than 5,000 portraits have been taken by E. Hart during the last ten years, in Sydney and Maitland, and are pronounced, by competent judges, equal to any from Europe.” 
 Sydney Morning Herald, 4 December 1852
 Sydney Morning Herald, 16 March 1854
 Maitland Mercury, 27 May 1854
 Maitland Mercury, 3 June 1854
 Maitland Mercury, 21 June 1854
 Maitland Mercury, 20-29 September 1854
 Maitland Mercury, 2 June 1855
 Maitland Mercury, 16 June 1855.
 Maitland Mercury , 24 October 1855
 Maitland Mercury, 27 October 1855
 Maitland Mercury, 12 January 1856
 Maitland Mercury, 24 Jan 1857
 Maitland Mercury, 3 September 1857
 Maitland Mercury, 9 March 1858
 Maitland Mercury, 10 August 1858
 Maitland Mercury, 29 August 1858
 Maitland Mercury, Saturday 13 August 1859
 Maitland Mercury, Saturday 26 November 1859
 Maitland Mercury, Saturday 24 December 1859