John Tennant Macfarlane was born John McFarlane on 29th April 1888 at 411 Dumbarton Road (the origins of ‘Tennant’ are unclear).
Number 411 is still standing, just by the corner of Merkland Street which is the short road to Partick Underground and Bus Stations. The whole corner property is called Peel House (Peel Road is directly opposite), the corner shop occupied by City Bakeries is number 401 and 411 is the shop with the white sign just to the right:

Here it is in 1969. City Bakeries is still there, 411 is now occupied by J.W. Galloway:

And today:

His father, James Mackie Macfarlane (1862-1897), was a spirit merchant who had grown up in Maryhill (his address on his marriage record is 104 Main Street, which I imagine to be in the Butney area). He married Mary Frew Baird (1861-1928) who had lost both her parents by the age of 24, in 1885.
John had an older sister, Mignon (she is one of only 15 children named Mignon born in the last 170 years, according to Scotland’s People).
In 1890 the family moved to 45 Bentinck St, Sandyford. In the 1891 Census they are recorded with baby James, one month old, and two servants

45 Bentick Street was built around 1877:

Argyle Street is at the top of the picture and Kelvingrove Park at the bottom.
From the wonderful glasgowwestaddress.co.uk website we also find John’s business (wine and spirit merchant) was at 180-182 Kelvinhaugh Street (link). This was probably a public house (in later years it was known as the Loch Sloy Bar, link) and in terms of the photo above it would have been off the photo in the top right (but evidently in easy walking distance).
This photo of a page in a book is from the late 1800s, I think:

I strongly suspect I copied it when it was posted on the Old Maryhill and Old Glasgow FB page, thank you to the original poster (likely Kenny Speirs). We’re on Maryhill Road looking north with Garbraid Avenue on the left and the Burgh Halls just visible – the aqueduct would be out of shot a little further up the road. But the interest for this post is the shop on the corner, James MacFarlane Wines and Spirits.
In 1892 the family moved to Bearsden. At the time the address was simply the villa name, Gowanbrae and it takes some tracking over time until street names and numbers are used to deduce this was probably 3 Chapelton Avenue:

John was educated at Glasgow Academy, including being a member of the Officer Training Corps.
In 1897 when John was near his 11th birthday, his father died, aged 34. It happened on 10th April at home; he was found dead and the record says “Probable cause suffocation sudden”. There must have been further investigation because the record of deaths includes a second page, dated 10th May and signed by the Procurator Fiscal, which gives the cause as “Accidental Suffocation”. The Milngavie and Bearsden Herald did not exist at the time and I cannot see any other newspaper reports, so that is all we know.
Almost exactly four years later the family was still at Gowanbrae with Mary described as “Living on own means”. All the children are at school and they have a servant, 1901 Census at Gowanbrae, 1 servant whose name was Bertha Julsen. She was 31 and from Norway.
Ten years later, three of the children still lived at home. Mignon has no stated occupation but may have helped her mother, whose occupation was given as “Wine merchant”. Mary McCallum, aged 23, from Slamannan in Stirlingshire. John, aged 23, was a bank teller, probably at Bank of Scotland in Milngavie.
I was interested in where the Milngavie office might have been and on checking the 1914 map I found that there was only one candidate:

I believe this is still standing and is now 39 Station Road, next to Kersland House Surgery.
He then seems to have moved between branches of the bank, working in Auchterarder (November 1910 to May 1913) and in Grantown-on-Spey. While in Auchterarder he was a part-time member of the 6th Battalion, the Black Watch ( a reserve battalion). He was also Secretary of the Literary Society.
John joined up on declaration of war in 1914 and was commissioned as a Lieutenant in the Motor Machine Gun Service, initially with the 1st Battery but by the time of the Battle of Loos nearly a year later with the 11th Battery. The Motor Machine Gun Service was equipped with Motor bikes and sidecars with a machine gun mounted. Unprecedented trench systems (from the North Sea coast to the Swiss border) had negated their main role. I have not seen it stated but assume they were used in an infantry role, detaching the guns.

A Battery in 1915 (not John’s unit, from Wikipedia link)
John’s battery would not have gone directly to France; there would have been basic training to do while in Britain. We can place him in Middlesex during this time because he was injured playing rugby and was treated at the Eastcote Voluntary Aid Hospital (in modern terms on the north-west edge of the London conurbation).
Britain had a very small army in Europe at the start of the war and the French bore the brunt of the German attacks. In 1915 they put pressure on the British to do more to share the burden and proposed an attack just south of Lille – this was to become known as the Battle of Loos.
Hill 70 was higher ground just south-east of the small town of Loos.

This is a modern Google Earth view, with Loos in the bottom left (and spreading all around the site – all of this would have been fields in 1914). The small city of Lens is in the top right distance. I’ve put a red circle around Hill 70 as otherwise I suspect you would not have described it as high ground but even slight elevations could offer observation points and a good field of fire for a machine gun, so were highly valued.

This photo is of the hill from ‘ground level’.
Fighting at Hill 70 was intense and John’s machine guns were supporting a battalion of Northumberland Fusiliers on 26th September (whether the 12th or the 13th battalion is unclear).
There are conflicting accounts about what happened. In one version, all the infantry officers had been killed or wounded and John led the troops in his area in several actions. Calling for an advance, the men were reluctant so he stood up and shouted words to the effect, “Come on boys, don’t be cowards!” and ran forwards where he was shot down within 50 yards.
I err towards the eyewitness account in a letter one of his men sent to his brother:
“[W]e put them back to Hill 70 where we lost our officer [Lieutenant John MacFarlane]. He dropped at my feet … Our machine guns held the Hill until we got reinforcements, when our men retreated. I lay on the top of the hill firing the gun without the legs for it, with my officer, when our Infantry ran back. We simply mowed [the Germans] down until our ammunition was finished. Then we had to run back too, for the Germans were bringing up reinforcements. It was when we were just on the parapet of our trench, about forty yards back, when my officer dropped at my feet. Poor soul! He did his bit. He stood beside me on the top of the Hill and shouted, “Come on boys, we have them on the run.”
[After he was wounded] I took him on a waterproof sheet for we could get RAMC men nowhere. So I got another chap from the Cycle Corps, and took him back to the nearest dressing station, which you had to crawl all the road to because of the shell and rifle fire.
It was pure hell from morning to night. However, we captured about fifteen thousand Germans, and the French had about fifteen thousand also, and fifteen to twenty big guns so we have done well. If we had just not lost our officer! He had an explosive bullet through his chest. The doctor said there was no hope for him …”

This poor-quality photo is from the Milngavie and Bearsden Herald shortly after his death.
He was buried in the garden of the last house on the right side of the road from Loos leading to Hill 70, according to a letter sent to his mother from the front; the house may well have been the location of the dressing station. However, the location was lost (probably in subsequent fighting) and his name is recorded at Dud Corner Cemetery on the Loos Memorial, a list of over 20,000 men killed in the battle with no known grave.

Footnote 1: family
Mignon MacFarlane married David Johnstone Clark. They lived at Glencarrin, Alder Road, Hill Park, Glasgow. One son, Stanley Frew Clark (born 1924). She died 17th November 1966. Stanley married Elsie Law in 1955 – their children were Louise, Iain and Elaine. Stanley died 2016.
James Baird MacFarlane, died 1951.
Edward Frew MacFarlane, married Annie McCallum in 1936. Ran the family’s bar on Maryhill Road (see below). Died 1944.
Footnote 2: the medal
On 24th January 1916, David Clark (John’s brother-in-law, Mignon’s husband) wrote to the War Office on behalf of John’s mother. Letters sent to her described the first version of his death above and suggested he had been put forward for a medal. A newspaper report also mentioned this, seemingly based on the letters.
This turned out to be incorrect and I can only interpret it as a misunderstanding, possibly based on the word of a junior officer – but only the Battery commander could put John’s name forward and he was elsewhere on this day.
Footnote 3: The Family Business
On the oldglasgowpubs website we find some information about the ownership of the Lochburn Bar, 1445 Maryhill Road:
There has been licensed premises on this site since the 1880s
John McFarlane was the founder of the business. He had been trading a grocer and provision dealer at 94 Main Street since the 1860s. He also traded as a Porter and Ale Dealer at premises at 93 Wyndford Street, Maryhill – he lived at 104 Main Street, Maryhill [birthplace of JTM’s father]
It was originally a white-washed cottage but was replaced by shops with tenements above in 1895
John MacFarlane [grandfather of JTM] died in 1894 but James [father of JTM] was owner and was also licensee of a pub at 180 Kelvinhaugh Street, many will remember this old pub as the Loch Sloy Bar.
The licence was transferred to Mary Frew Baird McFarlane as trustee of the late James McFarlane. Mary continued as licensee until the end of the First World War [actually until at least 1925].
Edward McFarlane was licensee during the 1930s, he was also the licensee of the Kelvinhaugh Street premises. When Edward passed away in 1950 his wife Anne took over as licensee. The pub was sold on in the 1950s and run by James Tresnan, he also ran the Old Wyndford Vaults across the road. The pub was finally demolished in the late 1970s.
Checking the Valuation Roll, by 1920 Mary was the owner of the entire 1895 block consisting of numbers 111, 113, 115, 117 Wyndford Street.