London Filth

A year ago I knew little about Victorian rubbish, however, in the course of home renovation I've had some personal contact with it.  Coal was the dominant fuel of the Victorian period and the first part of the 20th century with millions of homes burning it, there was a lot of ash to get rid off, not to mention the manure from the horses which which provided the motive power for much local urban transport.  I've found ash mixed with mortar in walls, as a filler in retaining wall cavities and in the bricks used for internal walls.  So far, no horse dung, but I have found some wooden paving blocks which were intended to minimize the noise of horse's hooves.  I have attempted to recycle some old bricks and hardcore and become aware that there are people seeking out the sites of ash tips.  The most exotic thing I found in my personal stash of the stuff was a broken egg cup, but some people find the lure of finding bottles and pot lids too strong to resist.  Then my son turns up with a book entitled:  "Dirty Old London - The Victorian Fight Against Filth". by Lee Jackson.

This book is well researched but wears its scholarship lightly and is an entertaining story about something that you might not want to contemplate at bedtime.  I'm only a short way into the book, but I now have a better understanding of my own rubble.  Around the middle of the 19th century, there was something which, with some stretch of the imagination, be called a virtuous circle.  At the time London was growing and this growth created  a demand for bricks, this in turn created a demand for ash, thus for a time, household rubbish had some value and its collection could be self financing.  Ash was useful for two reasons, the first because it was cheaper than clay (I'm assuming this) and secondly because it contained some un-burnt fuel which assisted the firing process.  As a personal observation, bricks with a high ash content are generally poor quality and me one wonder about building standards at the time.  Horse dung could be sold to farms and market gardens.  At that time brick making and market gardening were local industries and transport costs would have been reasonable, as London expanded, this ceased to be the case and domestic rubbish became a problem for local government.  Some innovative councils came up with the idea of using domestic rubbish as fuel for electricity generation which was a growth industry in the latter part of the 19th century, this was a nice idea, but coal did the job better.  As an aside, I spent half of  one of my teenage years on floating school on the lower reaches of the Thames, each day,  barges owned by the London County Council passed by on their way to dump rubbish at some point far enough away that it would not be returned with the flood tide.

As part of what I loosely call my day job, I'm messing with a cloud sky model for solar irradiance, part of this involves making an estimate of what the solar irradiance would be if the sky was clear.  Clear sky irradiance is influenced by atmospheric conditions.  Two significant variables are the quantities of aerosols and water vapor in the atmosphere.  Aerosols are fine particles, some are the result of natural processes like sand been blown off deserts in the dry summers and volcanic activity and some are due to human activity such as burning fossil fuels.  A gross over simplification would be, that all else being equal, you feel warmer/hotter under a dry, clean sky than under a dirty damp one.  Whilst attempting to understand some of variance between datasets, I downloaded some material from the NASA Earth Observatory (NEO) and plotted it on Google Earth.  The NEO is a wonderful resource for learning about the environment, it is a good combination of data, explanation and guidance for research.

Treat this plot of Aerosol Optical Depth for June 2011 with caution, the shading scheme is somewhat arbitrary and chosen to accentuate difference within a small sub-set of the data, my code could be buggy and human life is finite.

The aerosol content is higher in the dark squares than in the light ones and London stands out as a high spot.  This plot was an distraction from task in hand, but like the pot lid hunters I could not resist poking around.  In some way, it is a continuation of the story of urban filth.