In 1849 when the estate of Oswald was advertised for lease it consisted of 1000 acres and a house situated 8 or 9 miles from Maitland. The main road to and from the upper districts (from Maitland to Singleton) ran through the estate and the house was situated within a few hundred yards of the Main road. The house was substantial. Built of stone it contained eleven 'commodious and well finished rooms' on the ground floor. There were another six room upstairs and a kitchen and Stores were attached to the house and also made of stone with flagged floors.
The garden at Oswald extended for eight acres and was well stocked with fruit trees and vines with other cultivation on the banks of the river. A grass paddock of 400 acres fronting the river and 600 acres of bush run adjoined an extensive tract of government land and a large quantity of stock could be depastured in the open well grassed country.
Surveyor William Harper
The estate had belonged to surveyor William Harper who arrived in New South Wales almost 30 years previously.
Twenty-nine year old William Harper arrived in Hobart on 5th May 1821 with his wife Catherine and two children on the Westmoreland. On board the Westmoreland also were saddler Samuel Marsden, settler John West, runaway John Bisbee and Hunter Valley settler John Thomas Maughan.
William Harper had worked in Scotland as a surveyor for nine years before he came to Australia. He came with recommendations from Lord Bathurst. Sir John Oswald of Derrekere House also recommended him stating that he had employed Harper as a land surveyor on various occasions and he had uniformly executed the work he undertook and that he was a respectable, well-conducted young man and calculated to hold a situation of trust and confidence.
William Harper was also a cautious man. In a Memorial to Governor Macquarie dated 4th September 1821 it was revealed that he had brought with him property to the amount of six hundred and twenty pounds which he hoped to use in farming pursuits. He also possessed property in Edinburgh which he could have sold for seven hundred and fifty pounds previous to his departure but declined doing so until he should first see the certainty of succeeding in the colony. He must have liked what he saw because he soon wrote to his agent with instructions to sell this property and transmit him the proceeds of the sale. When he outlined his experience and training as a surveyor, he was given government employment as an assistant surveyor at the rate of 6/- per day for his services 
According to Henry Dangar's Index and Directory land had been granted to assistant surveyor William Harper in September 1820 . He requested a grant of land in September 1821 and in a reply two days later approval was given for an order for 700 acres of land and three convict servants.
He marked out the land in the district of Prospect, however on applying to the new Governor Sir Thomas Brisbane to have the land converted to a grant, he was informed that there could be no grant to a person holding a situation under the Crown.......however His Excellency would have no objection to giving him the occupation of some land exclusively reserved for him but without being a grant.....William Harper indignantly replied -
I beg leave to state to your Excellency that I have a wife and two children to support the great expense of living and travelling in the colony, the arduous duties and privation attending my situation and the consequent wear of clothes etc which my salary will not enable me to bear or replace.
His request for an allotment of land in the township of Newcastle was also denied. William Harper increased his holdings by purchase - he was included on a list of persons who held warrants for purchase of 1000 acres of Crown land in 1825. In addition he applied for separate lots of 900 and 680 acres in 1834.
In the Journal of the Royal Australian Historical Society, Volume 39 - The Life and Times of Henry Dangar, E.C. Rowling mentioned William Harper:
At the beginning, it will be recalled, William Harper and Henry Dangar were appointed assistants to the Surveyor-General at a salary £109/10/- per annum. From the beginning of January, 1823, this was increased to £200 per annum without any allowances, Dangar being designated Second Assistant (Harper being the first).......... Lord Bathurst wrote to Governor Darling on December 12, 1826, to inform him that Henry Dangar was to have an increase of £50 per annum in salary upon the retirement of William Harper, the First Assistant, into whose position he was to step.
The above mention of retirement seems to be an indication that William Harper may have lost his sight as early as 1826 as he was said to have been deprived of his sight whilst still in government service.
Harper sold his theodolite to government in 1831 and retreated to his Oswald estate with Catherine and their young family. Elizabeth was born in 1819, son William in 1821, George in 1823, Mary in 1826 and Francis in 1829.
Life as a Settler
William Harper was an acquaintance of George Wyndham of Dalwood and is frequently mentioned in George Wyndham's Diary. They exchanged information about crops, weather conditions, geology and presumably about construction of buildings as one entry against William Harper notes Edificatures, and both were building their rather magnificent houses around the same time. In another curious entry on the 21st February 1833 George Wyndham remarked 'the blacks are saucy in Mr. Harper's brush' and on 22nd April 1833 he noted that Mr. Harper had been robbed by two men.
This was bushrangers Henry Beard and John Richardson who were afterwards executed. Soon afterwards, William Harper put his signature on the petition to the Legislative Council regarding the Summary Punishment Bill.
In the mid 1830's William Harper was visited by Dr. Thomas Parmenter who referred to him as the blind philospher.....After travelling nearly all day the excellent and incomparable new road we just had a sight of Mr. Duguid's cottage and excellent well laid out grounds; and to my no small astonishment, we came upon a sudden burst and magnificent view of 'Oswald Seat' the mansion of that unfortunate professional gentleman Mr. (William) Harper Ah! methought, sympathy and similarity of condition often inciting me to call I will not pass such a man of talent's door without paying my respects; and I need not have cogitated on the matter as Mrs. Harper hospitably came out, and anticipated all my fire and feeling. I had never seen him before. Depicture to yourself a young man in the prime of life, completely blind; but oh! the light of his varied features and animated discourse, and what, thought I, Call you this an affliction, when by his genius and taste, he has contrived and planned a mansion surpassing any I have seen on the Hunter. Just picture nearly three hundred acres stumped and tastefully laid out, with rising terrace and romantic hill, surrounded by valleys of a tortuous aspect, and on the summit of which towers an edifice for elegant splendour and locality of design, in the castellated modern fashion of comfort and grandeur assimilated Here could I pass my days, did not a paramount duty call me home to my improvising seat and retreat, purposely to enjoy his right and sight of intellect, though blind to external objects, yet illuminating all by his mind's eye, ever busy and never ceasing gaze. What smiles and joy, so pure as Home; When sweet content does crown the scene' 'Well I must go, said I to the 'Blind Philosopher', for in no other light could I contemplate the enlightened Mr. Harper, for my patients will be expecting me'
Assigned Convict Servants
Some of the convicts who were assigned to William Harper at Oswald included the following:
Search here to find out more about the convicts mentioned below
Charles Williams per Prince Regent
Thomas Coyle per John Barry
Lucy Sweeney per Elizabeth
David Gardner per Marquis of Hastings
Michael Healy per Boyne
Patrick Halfpenny per Boyne
John James per Marquis of Hastings
John McMullen per Asia
James O'Hara per Henry Porcher
Charles Templar per Countess of Harcourt
Lucinda Sweeney per Elizabeth
James Hartnett per Governor Ready
Edward Murphy per Sophia
John Hickie per Sophia died in 1836.
Grace Bryant per Roslin Castle
Johanna Corcoran assigned servant in 1831
Thomas Reilly per Hercules
Mary Shanahan per Brothers
John Cooper per Portland
Ann McNamara per Palambam
Joseph Mills per Camden
John Dean per Isabella
Arthur O'Brien per Hercules
Catherine Brady per Andromeda
Ann Elliott per Fanny
Catherine Kent per Andromeda
William Barnes per Adrian
Catherine Harper was left to bring up her young family on her own, the youngest being only about six or seven years old in 1836.
William Harper Junior
William junior was fifteen when his father died and although he probably assisted his mother in running the estate, over the next fifteen years the estate dwindled by half. At first, part of the estate was divided into small farms to be run by tenants. William junior sometimes became embroiled in disputes with the tenants such as John Locke and William Cole over straying cattle and land leases By 1848 portions of the estate were for sale. William junior was seriously injured when gored by a cow in 1847 and was under the care of Dr. McCartney for several days. However he made a complete recovery and was able to marry Emma Grace Marshall three months later in June 1847. Grace Marshall, was the daughter of Lieut. Sampson Marshall.
In 1849 a servant of William Harper had a narrow escape after a confrontation with bushrangers James Davidson and William Smith. The district was in uproar when on a Sunday afternoon in June, the mail coach from Singleton to Maitland was stopped and robbed by the two armed men
...... A Short time before sundown the mail had reached Mr. Harper's gate, about two miles from Lochinvar, when two men sprang from behind a large fallen tree, and ordered the driver to stop, each at the same time presenting a double barreled carbine, cocked. The driver pulled up, and the larger of the two men ordered him to throw out the mailbags. This order was also obeyed, the carbines of the bushrangers being within a few feet of the driver and Mr. Loxton, a passenger, and one pointed at each. The bushrangers now ordered the driver to move on a stop or two, the smaller man accompanying him as a guard, with his piece presented. The other bushranger then cut open the mailbags and selected there from a great quantity of letters, many apparently registered, which he opened, and took the contents from. Having finished a cool inspection of the bags, and ransacked all the letters that he desired, he gathered the letters into a heap lit a match, and set fire to them. The empty mailbags were thrown back into the coach. The passengers Mr. Loxton and Mrs. Kerrigan were also forced by the bushrangers to give up what silver they had about them, fortunately in each case only a few shillings, The shorter bushranger while standing guard, with his gun presented and cocked, appeared quite nervous, his hand trembling so much that Mr. Loxton feared he would draw the trigger unintentionally. During the time the coach was being thus plundered, a horseman came up, and was stopped by the bushrangers; and shortly after Mr. Doolan, an elderly man came up on foot, and was ordered by the bushrangers to hold the first man's horse. A servant of Mr. Harper's, named John Porter was at that time coming from Harper's ground on to the road, and was crossing it, when the taller bushranger presented his piece at him and told him to hold the bridle of his horse or he would blow his brains out. Porter complied, and afterwards, when the letter ransacking was finished, he was relieved by the shorter bushranger, and employed to hand back the empty mail bags; Porter was then ordered by the bushrangers as the coach drove off, to come back, but he ran for it, and getting under the fence, made for home at full speed; a gun was fired at him and Porter heard the ball whiz by him, but did not relax his speed; the shorter bushranger shortly after overtook him, but Porter knocked him down with a stick he had picked up, and got safely home to Oswald.'
Oswald for Lease
In 1849 William Harper (junior) decided to leave the district and leased out Oswald. Charles Ferdinand Hamilton Smith husband of William's sister Elizabeth also put his estate of Engheim at Harper's Hill up for lease at the same time. They moved for a time to Wee Waa where Captain Smith was employed as Magistrate until at least 1851. Later Elizabeth and Captain Smith returned to Oswald. He died there in July 1862 aged 53 years. Elizabeth died at Branxton in December 1889.
Destroyed in a Fire
The Singleton Argus reported the sad end of Oswald House which was destroyed in disastrous bush fires in December 1944....
More than half a million men last night were fighting fires which had turned great areas of the State into an inferno. Damage already runs into millions of pounds. Miss Jane Cavanagh, 80, was burned to death when flames enveloped the stone homestead of Oswald House at Oswald (near Lochinvar) yesterday. Other adults and three children had narrow escapes from Oswald House. They saved nothing except the clothes they wore. Cows bailed up for milking were burned to death. Mr. R. Ekert, of Oswald said the flames travelled like a whirlwind. Picked up by the gale that was blowing at the time burning manure scattered the flames over a wide area. The shingles under the roof at Oswald House caught alight and seemingly in a moment the house was enveloped in flames. Mr. Ekert added. 
 Index to map of the country bordering upon the River Hunter... by Henry Dangar (London : Joseph Cross, 1828). p5
 Sydney Gazette 3 October 1825
 Sydney Herald 16 January 1839
 Singleton Argus 11 December 1944
 Journal of the Royal Australian Historical Society, Volume 39
 Ancestry.com. New South Wales, Australia, Colonial Secretary's Papers, 1788-1825 Series: (NRS 899) Memorials to the Governor, 1810-1825 Item: 4/1826 Number: 59
 Ancestry.com. New South Wales, Australia, Colonial Secretary's Papers, 1788-1825 Series: (NRS 937) Copies of letters sent within the Colony, 1814-1825 Item: 4/3504 Page: 309
 Ancestry.com. New South Wales, Australia, Colonial Secretary's Papers, 1788-1825 Series: (NRS 938) Copies of letters sent and received, mainly within the colony, or 'Document books Nos. 1-3', 1817-1825
 Ancestry.com. New South Wales, Australia, Colonial Secretary's Papers, 1788-1825Series: (NRS 899) Memorials to the Governor, 1810-1825 Item: 4/1830 Number: 152