1840: BOATRACE - Cambridge won by three quarters of a length. Westminster to Putney. See Boatrace 1836-42
1840: HEAD OF THE RIVER - Brasenose

1841: BOATRACE - Cambridge won by 1 minute 5 seconds. Westminster to Putney. See Boatrace 1836-42
1841: HEAD OF THE RIVER - University College

1842: BOATRACE - Oxford won by 13 seconds. The last Westminster to Putney boatrace. See Boatrace 1836-42
1842: HEAD OF THE RIVER - Oriel
Sherwood says: 'The race for head of the river on the fifth night is that described in 'Tom Brown at Oxford', 'St Ambrose' being Oriel, and Oriel, Trinity"

[ Oriel ('St Ambrose'], started 5th and made three consecutive bumps, then rowed over in 2nd place, and then on this 5th night bumped Trinity(called 'Oriel' below). They then rowed over twice as head boat.
The illustration of the start in 'Tom Brown at Oxford' shows an outrigged boat which. according to Sherwood, Oriel did not use until 1845 - so I have transferred it to that year

The jackets were thrown on shore, and gathered up by the boatmen in attendance. The crew poised their oars, No. 2 pushing out her head, and the Captain doing the same for the stern.  Miller took the starting-rope in his hand.
"How the wind catches her stern," he said;
"here, pay out the rope one of you. No, not you - some fellow with a strong hand. Yes, you'll do," he went on, as Hardy stepped down the bank and took hold of the rope;
"let me have it foot by foot as I want it. Not too quick; make the most of it - that'll do. Two and three just dip your oars in to give her way."
The rope paid out steadily, and the boat settled to her place. But now the wind rose again, and the stern drifted towards the bank.
"You must back her a bit, Miller, and keep her a little further out, or our oars on stroke side will catch the bank."
"So I see; curse the wind. Back her, one stroke all. Back her, I say!" shouted Miller.
It is no easy matter to get a crew to back her an inch just now, particularly as there are in her two men who have never rowed a race before, except in the Torpids, and one who has never rowed a race, in his life.
However, back she comes; the starting rope slackens in Miller's left hand, and the stroke, unshipping his oar, pushes the stern gently out.
There goes the second gun!  One short minute more, and we are off.  Short minute, indeed!  You wouldn't say so if you were in the boat, with your heart in your mouth, and trembling all over like a man with the palsy.  Those sixty seconds before the starting gun in your first race why, they are like a life time.
"By Jove, we are drifting in again," said Miller, in horror.  The Captain looked grim, but said nothing; it was too late now for him to be unshipping again. 
"Here, catch hold of the long boat-hook, and fend her off." Hardy, to whom this was addressed, seized the boat-hook, and, standing with one foot in the water, pressed the end of the boat-hook against the gunwhale, at the full stretch of his arm, and so, by main force, kept the stern out.  There was just room for stroke oars to dip, and that was all.  The starting rope was as taut as a harp-string; will Miller's left hand hold out?
It is an awful moment.  But the coxswain, though almost dragged backwards off his seat, is equal to the occasion.  He holds his watch in his right hand with the tiller rope.
"Eight seconds more only.  Look out for the flash.  Remember, all eyes in the boat."
There it comes, at last the flash of the starting gun.  Long before the sound of the report can roll up the river, the whole pent-up life and energy which has been held in leash, as it were, for the last six minutes, is let loose, and breaks away with a bound and a dash which he who has felt it will remember for his life, but the like of which, will he ever feel again?  The starting ropes drop from the coxswain's hands, the oars flash into the water, and gleam on the feather, the spray flies from them, and the boats leap forward.
The crowds on the bank scatter, and rush along, each keeping as near as it may be to its own boat.  Some of the men on the towing path, some on the very edge of it, often in, the water some slightly in advance, as if they could help to drag their boat forward some behind, where they can see the pulling better but all at full speed, in wild excitement, and shouting at the top of their voices to those on whom the honour of the college is laid.

"Well pulled all!"
"Pick her up there, five!"
"You're gaining every stroke!"
"Time in the bows!"
"Bravo, St.Ambrose!"
On they rushed by the side of the boats, jostling one another, stumbling, struggling, and panting along. For a quarter of a mile along the bank the glorious maddening hurly-burly extends, and rolls up the side of the stream.
The St. Ambrose's boat is well away from the boat behind, there is a great gap between the accompanying crowds;  and now, as they near the Gut, she hangs for a moment or two in hand, though the roar from the bank grows louder and louder, and Tom is already aware that the St. Ambrose crowd is melting into the one ahead of them.
"We must be close to Exeter!"  The thought flashes into him, and it would seem into the rest of the crew at the same moment.  For, all at once, the strain seems taken off their arms again;  there is no more drag;  she springs to the stroke as she did at the start;  and Miller's face, which had darkened for a few seconds, lightens up again. Miller's face and attitude are a study.  Coiled up into the smallest possible space, his chin almost resting on his knees, his hands close to his sides, firmly but lightly feeling the rudder, as a good horseman handles the mouth of a free-going hunter, - if a coxswain could make a bump by his own exertions, surely he would do it.  No sudden jerks of the St. Ambrose rudder will you see, watch as you will from the bank;  the boat never hangs through fault of his, but easily and gracefully rounds every point. 
"You're gaining!  You're gaining!" he now and then mutters to the Captain, who responds with a wink, keeping his breath for other matters.  Isn't he grand, the Captain, as he comes forward like lightning, stroke after stroke, his back flat, his teeth set, his whole frame working from the hips with the regularity of a machine?  As the space still narrows, the eyes of the fiery little coxswain flash with excitement, but he is far too good a judge to hurry the final effort before the victory is safe in his grasp.
The two crowds are mingled now, and no mistake;  and the shouts come all in a heap over the water. 
"Now, St Ambrose, six strokes more."
"Now, Exeter, you're gaining;  pick her up." 
"Mind the Gut, Exeter."  "Bravo, St Ambrose."
The water rushes by, still eddying from the strokes of the boat ahead.  Tom fancies now he can hear their oars and the workings of their rudder, and the voice of their coxswain.  In another moment both boats are in the Gut, and a perfect storm of shouts reaches them from the crowd, as it rushes madly off to the left to the foot-bridge, amidst which
"Oh, well steered, well steered, St. Ambrose!" is the prevailing cry. 
Then Miller, motionless as a statue till now, lifts his right hand and whirls the tassel round his head; 
"Give it her now, boys;  six strokes and we are into them."  Old Jervis lays down that great broad back, and lashes his oar through the water with the might of a giant, the crew catch him up in another stroke, the tight new boat answers to the spurt, and Tom feels a little shock behind him and then a grating sound, as Miller shouts,
"Unship oars bow and three," and the nose of the St. Ambrose boat glides quietly up the side of the Exeter, till it touches their stroke oar.

Read all the rowing material in Tom Brown at Oxford here

Oxford University Boat Races, 1842 -

Oxford Racing 1842
Oxford University Boat Races, 1842

However there was, for Oxford rowing, a very significant Oxford and Cambridge Race at Henley Regatta. This description comes from Alice in Waterland by Mark Davies:
In Reminiscences, 1907, the Rev. W Tuckwell called this 1843 race at Henley:

the event which really popularized boating in Oxford; but college races were, before that year, a mere pleasant incident in a summer term, there were no college barges on the River; even the Oxford and Cambridge race, except in 1829, the first race rowed, excited language interest.

The circumstance which made the 1843 race so special was that Oxford triumphed despite being a man down.
The all-important position of stroke was filled by an exceptional oarsman called Fletcher Menzies, who had inspired a great improvement in the Oxford performance, after several years of Cambridge victories.
Expectations were high.
Then just before the race, [actually when seated in the boat!] Menzies was suddenly taken ill and had to withdraw. As the rules permitted no substitute, the seven men of Oxford, 'hopeless of more than a creditable defeat', as Tuckwell put it, took to their oars.
Thomas Hughes' brother George was a member of the crew, and he switched position to row stroke.
Despite the odds, Oxford won.
Hysterical celebrations followed, as witnessed by Thomas Hughes, who recorded in Memoir of a Brother, 1873,

The crew had positively to fight their way into the hotel, and barricade themselves there, to escape being carried round Henley on our shoulders.
The enthusiasm, frustrated in this direction, bust out in all sorts of follies, of which you may take this as a specimen.
The heavy tollgate was pulled down, and thrown over the bridge into the River, by a mob of young Oxonians headed by a small, decorous, shy man in spectacles, who had probably never pulled an oar in his life.

One effect the seven oar race had on our generation at Oxford: it made boating really popular, which it had not been till then,

wrote Thomas Hughes, who himself took up rowing soon after, with instant success he was in a victorious Oriel College four oar crew the following year.
His brother George was Captain, and no man ever knew better when to give his crew the long Abingdon reach, and when to be content with Iffley and Sandford.
At the half hour's rest at those places he would generally sit quiet, and watch the skittles, wrestling, quoits, or feats of strength which we're going on about. His overall verdict was that

there are few pleasant and memories of my life than those of the riverside.

1843: HEAD OF THE RIVER - University College
Floods all the time. Dates altered to avoid clashing with the Derby. On the second night St John's through an accident, started with seven oars; on the fifth Brasenose ran aground.

1844: HEAD OF THE RIVER - Christchurch
In 'Tom Brown at Oxford' Thomas Hughes describes the procession of boats during a commemoration of the 1840s:

The barges above and below the university barge, which occupied the post of honour, were also covered with ladies, and Christchurch meadow swarmed with gay dresses and caps and gowns.
On the opposite side the bank was lined with a crowd in holiday clothes, and the punts plied across without intermission loaded with people, until the groups stretched away down the towing path in an almost continuous line to the starting place.
Then one after another the racing boats, all painted and polished up for the occasion, with the college flags drooping at their sterns, put out and passed down their stations, and the bands played, and the sun shone his best.

1845: BOATRACE - Cambridge won by 30 seconds. The first Putney to Mortlake boatrace. See Boatrace 1845-49
1845: HEAD OF THE RIVER - Brasenose

Bumps Start, Tom Brown at Oxford, 1861
Oriel at the Start at Iffley from Tom Brown at Oxford, 1861.
The story given applied to 1842, but 1845 was the first year in which Oriel used outriggers.

1846: BOATRACE - Cambridge won by 3 lengths. See Boatrace 1845-49
1846: HEAD OF THE RIVER - Brasenose
Blackwood's Edinburgh Magazine 1846 - [ I cannot reconcile this with Sherwood ] -

It was the last night of the boat races. All Oxford, town and gown, was on the move between Iffley and Christchurch meadow. The reading man had left his ethics only half understood, the rowing man his bottle more than half finished, to enjoy as beautiful a summer evening as ever gladdened the banks of Isis.
One continued heterogeneous living stream was pouring on from "St Ole's" to King's barge, and thence across the river in punts, down to the starting place by the lasher. One moment your tailor puffed a cigar in your face, and the next, just as you made some critical remark to your companion on the pretty girl you just passed, and turned round to catch a second glimpse of her, you trod on the toes of your college tutor.
The contest that evening was of more than ordinary interest. The new Oriel boat, a London-built clipper, an innovation in those days, had bumped its other competitor easily in the previous race, and only Christchurch now stood between her and the head of the river. And would they, could they, bump Christchurch tonight? That was the question to which, for the time being, the coming examination, and the coming St Leger, both gave way.
Christchurch had not been bumped for ten years before - whose old blue and white flag stuck at the top of the mast as if it had been nailed there - whose motto on the river had so long been "Nulli secundus?"
It was an important question, and the Christchurch men evidently thought so. Steersmen and pullers had been summoned up from the country, as soon as that impertinent new boat had begun to show symptoms of being a dangerous antagonist, by the rapid progrees she was making from the bottom towards the head of the racing-boats.
The old heroes of bygone contests were enlisted again, like the Roman legionaries, to fight the battle of their "vexillum", the little three-cornered bit of blue and white silk before mentioned; and the whole betting society of Oxford were divided into two great parties, the Oriel and the Christchurch, the supporters of the old, or of the new dynasty of eight oars.
Never was signal more impatiently waited for than the pistol-shot which was to set the boats in motion that night. Hark!
"Gentlemen, are - you - ready?"
"No, No!" shouts some umpire, dissatisfied with the position of his own boat at the moment.
"Gentlemen, are you ready?" Again
"No, no, no!" How provoking! Christchurch and Oriel both beautifully placed, and that provoking Exeter, or Worcester, or some boat that no one but its own crew takes the slightest interest in tonight, right across the river! And it will be getting dusk soon. Once more - and even Wyatt, the starter, is getting impatient -
"Are you ready?" Still a cry of
"No, no," from some crew who evidently never will be satisfied. But there goes the pistol.
They're off by all that's glorious!
"Now Oriel!"
"Now Christchurch" Hurrah! beautifully are both boats pulled - how they lash along the water! Oriel gains evidently! But they have not got into their speed yet, and the light boat has the best of it at starting.
"Hurrah, Oriel, its all your own way!"
"Now Christchurch, away with her!"
Scarcely is an eye turned on the boats behind; and indeed, the two first are going fast away from them. They reach the Gut, and at the turn Oriel presses her rival hard. The cheers are deafening; bets are three to one. She must bump her!
"Now Christchurch, go to work in the straight water!" Never did a crew pull so well, and never at such a disadvantage. Their boat is a tub compared with Oriel. See how she buries her bow at every stroke.
Hurrah, Christchurch! The old boat for ever! Those last three strokes gained a yard on Oriel! She holds her own still! Away they go, those old steady practised oars, with that long slashing stroke, and the strength and pluck begins to tell. Well pulled Oriel! Now for it! Not an oar out of time, but as true together as a set of teeth.
But it won't do! Still Christchurch, by sheer dint of muscle, keeps her distance, and the old flag floats triumphant another year.

1847: HEAD OF THE RIVER - Christchurch

A quaint accident befell Brasenose, which is thus described in the Oxford Herald:

On Wednesday, May 19, Brasenose met with an unfortunate and un-looked for accident. On passing the Cherwell they were some considerable distance ahead of Christchurch, and were rowing beautifully towards home, when, just as the head of the boat was passing the red flag, one of the crew caught a 'crab', and in endeavouring to recover himself, was thrown completely out of the boat into the river, and as the boat was thrown on its side it shipped a considerable quantity of water. The seven oars had not the least chance to pull the boat past the flag, as all the oars on bow side were in the air, and stroke side deep in the water.

In consequence of this accident Christchurch bumped them on the post.

[ Thinking about this accident - this was in the very early years of outriggers when balancing a boat was a fairly recent concept. If you look at the 1845 picture taken from 'Tom Brown at Oxford' you will see that there is no gate on the rigger but simply two posts between which the oar rests. When a boat tips the oars on that side will be raised. A gate would protect from capsize - but these posts mean that the oar will float up away from the rigger and give no protection. The oarsman could do nothing about that. ] Oxford won the Grand at Henley Regatta against Thames Club.

1848: HEAD OF THE RIVER - Christchurch
Oxford again won the Grand at Henley Regatta against Thames Club.

Oxford Rowing Colours 1848 -

Oxford Colours 1848
Oxford Colours 1848
Oxford Colours 1848
Oxford Colours 1848
Oxford Colours 1848
Oxford Colours 1848
Oxford Colours 1848

[ I recognise several of my contemporaries! ]

1849: BOATRACE MARCH - Cambridge won by 1 minute. See Boatrace 1845-49
After Oxford's disastrous defeat in March they challenged Cambridge to a re-row in December 1849. Cambridge gallantly made the mistake of accepting ...
1849: BOATRACE DECEMBER - Oxford won after a foul by Cambridge. See Boatrace 1845-49
1849: HEAD OF THE RIVER - Christchurch