Stepped buttresses

Buttresses are very common, almost ubiquitous, on church buildings of this age, we are talking a complete rebuild between 1371 and 1419 so, of course St Nick's has its share. They strengthen the wall and hold up the roof trusses preventing them from pushing out the walls. Between each buttress there's a window to let in the light and also a glass window weighs less than solid  stone or brick so keeping building's weight and costs down (every little helps). Obviously a tall spire needs supporting and good buttresses do the job.

In this picture you can see the second doorway on the north side. Behind this wall a pitched roof leads to the clerestory which to my regret I haven't got a good picture except for a slight peek in the one below. (This picture shows the clerestory from the other side). The clerestory is supported by internal pillars as I showed way back in this post.

Now no doubt you'll be delighted to hear that to all intents and purposes the church is  symmetrical so the south side looks much like the north save for a porch that I mentioned yesterday and the base of the spire.

...and I've just realised that this was rebuilt some twenty years after the Black Death killed a third to half the population of England, no taking silly test tests to see if you had the lurgy back then, no godforesaken masks either just: Attishu, attishu, we all fall down. No doubt twenty years from now they'll still be waiting for their precious vaccine while face masks will have become implanted hermetically at birth along with health passports courtesy of the Gates Foundation...

Arc-boutant

Arcs-boutants also known as a flying buttresses; these devices transmit the force of the ceiling through the wall to a counterweight outside the building. It means the walls can be thinner and allows more space inside the building. They were extensively used in mediaeval ecclesiastical buildings. However the ones you see here, at St Mary's, Beverley, were put up in the 1850s in a restoration job by Augustus Welby Pugin, his son E Welby Pugin, and Sir Gilbert Scott.
They fit in well and do look pretty cool with the light shining through.