history

Which direction? At Jacob the Angel, Neal’s Yard

Jacob the Angel, coffee Covent Garden
It is easy to miss Jacob the Angel as you enter Neal’s Yard, but an angel above the hoarding gives it away.

Jacob the Angel is tucked into Neal’s Yard in London’s Covent Garden. Named after Thomas Neale (1641-1699), Neal’s Yard is part of his development which is now known as Seven Dials. And rather like the larger 17th century development, this cafe-physics review of Jacob the Angel has a similar dilemma: so many avenues to explore, each wrestling for attention, which one to pursue?

But first the coffee. Roasted by Square Mile, coffee is available as the usual espresso based drinks or on V60 pour over. I had a Rwandan V60 that was full bodied and full of treacle like flavours. Owing to the geometry of the cafe, I didn’t get to check my ‘flavour notes’ against what the tasting notes thought I should perceive. The cafe space itself is fairly small but with a surprising amount of seating. Given this, it can feel a bit close as you squeeze past some of the people sitting down in order to place your order, (hence not double checking the tasting notes) however that is quickly set aside as you can gaze at the large selection of cakes (all with allergens clearly marked) arrayed on the counter.

On the walls of the cafe were paragraphs about the history of coffee and how a man named Jacob opened Britain’s first Coffee House in 1651 at the Angel Inn (in Oxford). The coffee itself came presented in a manner that was reminiscent of solar eclipses, while the sink next to our table was strikingly similar to those in my A-level chemistry lab. Unable to dissociate my memories of the sink with the reality of the environment at Jacob the Angel, it was a bit shocking when someone came to fill their glass of tap water there – don’t they realise what could have been in that sink?! Each thought train surfacing as a potential direction for the review, but then, above me, something moved. Looking up it was clear that a plant that was hooked to the ceiling was moving in a draught, but where was the breeze coming from? A small air-conditioning/heater unit was on the other side of the coffee house, circulating the air that was moving the plants.

plants, Jacob the Angel, Coffee Covent Garden
Plants above the tables at Jacob the Angel. How do they move in the breeze?

The moving plant had appeared to my peripheral vision as if it was floating in the breeze or perhaps flying. Now clearly there cannot be a flying plant, but in some ways the swaying leaves do illustrate the fluidity of air, which is a necessity for flight. The moving air demonstrates how the air imparts a force to the leaves (and the pot) causing them to sway. For things that genuinely fly this would be experienced as ‘drag’ – something that we have probably all experienced, even when not flying. Drag is increased if the object moving through the fluid (air) has a larger surface area perpendicular to the direction of movement: all being equal, bigger objects experience more drag. Imagine moving a spoon through coffee, it is easier to move a stirring stick rather than a tablespoon. But then, drag also depends in a non-trivial way on the shape of the object and how that changes the vortex wake behind it (look again at the spoon and how the vortices form behind it as it is dragged through coffee, you do not see those so easily with a stirring stick).

It is partly this sort of shape effect that seems to be behind Orsted’s recent restatement of the calculation of the amount of energy that their off shore wind farms can generate. By actually going out and measuring the air flow around the off shore wind farms, Orsted discovered that the air flow (which would be used to generate power) is affected not just by the individual windmill (as had been known and calculated), but its neighbours and the way these combine into the shape of the wind farm. There is still a lot we don’t understand about exactly how spoons move through coffee.

vortices in coffee
Vortices behind a spoon dragged through coffee.

But there is also a connection to a different type of “flying machine” if only through the name of the coffee house. For it was from the Angel Inn in (what is now) Aldwych that, more than 250 years ago, that an unusual ‘flight’ took place*. It was described in an advertisement in the paper:

“On Monday, the 5th of April 1762, will set out from the Angel Inn behind St Clements Church in the Strand…. a neat flying machine, carrying four passengers, on steel springs and sets out at four o’clock in the morning, and goes to Salisbury the same evening, and returns from Salisbury the next morning at the same hour… Each passenger to pay 23 shillings for their fare, and to be allowed 14lb weight baggage”.

How many more avenues could be followed while enjoying a slow coffee at this small but fascinating little cafe? Do let me know what you ‘see’ next time you visit.

Jacob the Angel is in Neal’s Yard, Seven Dials, London.

*”London Coffee Houses” by Bryant Lillywhite, pub. 1963

Rosie and Joe, St Giles churchyard

Coffee in a Wake Cup at Rosie & Joe in St Giles. The space rewards those who notice.

There is a long history of hospitality on the site of St Giles in the Fields stretching back far earlier than the Notes coffee barrow. But Rosie & Joe is a lovely iteration to that tradition. There’s a definite focus on tea at Rosie & Joe but the coffee is roasted by Square Mile and prepared on a La Marzocco machine. There is also a good selection of food to nibble on (as well as more food stalls nearby on weekday lunchtimes). And although it is a cart, there are a few seats and tables dotted around so it is easy to sit back and enjoy your coffee while the world races by.

St Giles High St is a very busy road and yet, sitting in the churchyard of St Giles is strangely peaceful. Despite the traffic and the occasional siren, it is one of those rare places in London that you can find the stillness to listen. A beautiful place to enjoy a coffee from an independent stall in fact! And if you have your own cup with you, there is even 10p off your coffee. The coffee was smooth and sweet, fruity but definitely a sweet and full bodied type of fruity cup. But why was it so peaceful? Was it merely that it was a lovely (but breezy) spring morning when I tried Rosie & Joe? Or was it that it is a small bit of nature in a built up environment? Both of these helped but I think it is also the way that the place rewards those who notice by offering more each time you look.
The ghost sign hidden behind the tree just outside the churchyard.

There’s the, perhaps slightly grim, history suggested by the fact that the ‘garden’ is significantly raised above the level of the pavement in parts. There’s the brickwork and stone walls of the church itself of course. The ‘ghost sign’ on a nearby building that is revealed to the coffee drinker by the fact that the tree between us and it has not yet got its summer leaves. And then the nod to the history of the site hinted at by the coffee cart itself: Since Matilda, wife of Henry I founded St Giles’ leprosy hospital on the site, a “cup of charity” was given to condemned prisoners as they made their way past St Giles on their way to their execution at Tyburn*. Very different now, but the tradition of refreshment for the traveller is continued.

But then a fire engine’s siren reminds you that you are in a cosmos, a universe filled with beautiful physics. You know whether the fire engine is approaching or has passed away from you from how the pitch of the sound changes as it goes past. The Doppler shift meaning that sound waves travelling towards you have a shorter wavelength (higher frequency, higher pitch) than those travelling away (longer wavelength, lower frequency, lower pitch). And part of the beauty of physics is that it is so universal; what works for sound also works for light. If an object emitting light is moving away from us, the light appears to have a longer wavelength (lower frequency, it is red-shifted) than if the same object were stationary or moving towards us where it would appear as if it emitted light with a shorter wavelength (higher frequency, blue shifted).

signboard at Rosie and Joe
Doesn’t a right imply a duty? There’s a lot that could be said about #supportindependent
So, similarly, if we were to look at the surface of a rotating planet and saw how the light reflected off that planet’s surface, the side of the planet that was rotating towards us would look ever so slightly bluer than the side rotating away from us which would look slightly redder. And if the planet’s surface was like Venus and obscured by clouds (rather like the ghost sign at Rosie & Joe will be obscured by leaves in a couple of months time) we could use the reflection of radio waves from the surface rather than visible light to see the same red-shift/blue-shift in the radio waves as the planet rotates**. In this way we could determine the direction of rotation of the planet and how fast it was rotating just as we get an indication of the speed of the fire engine from listening to the sound of the siren.

The siren takes us from a consideration of inner stillness to a recognition of the scale of the universe. Which is rather apt for a cafe in a churchyard, where the architecture of a church is often designed to be read symbolically, from the person to their place in the grand scheme of things***. One great thing about this particular cafe though was how much there was to see that cannot be included in this cafe-physics review for reasons of space. The location truly rewards those who pay attention to what they notice here. I can only recommend that you take some time out, take your re-usable cup and go to find some time to enjoy your coffee (or tea) in this quiet space in central London.

*The London Encyclopaedia, 3rd Edition, Weinreb et al., 2008

**Astronomy, the evolving universe, 6th Edition, Zeilik, 1991

***How to read a church, Taylor, 2003

Rosie and Joe can be found in St Giles in the Fields churchyard, Monday-Friday.