Grouped under these sub-headings:
On this site (compiled from various sources)
The quality of the following firewood is based upon various characteristics such as its speed of burn, heat given off, tendency to spark (spit), ease of splitting, time required to season, etc
Grade: 1 = Poor. Grade: 2 = Low. Grade: 3 = Good. Grade: 4 = High.
|Common Name||Botanical Name||Comments|
|Alder||Alnus||A low quality firewood. Grade: 1|
|Apple||Malus||Needs to be seasoned well. Burns well with a pleasant smell and without sparking/spitting. Grade: 3|
|Ash||Fraxinus||Considered to be one of the best woods for firewood. It has a low water content (approx. 50%) and can be split very easily with an axe. It can be burned green but like all wood is best when seasoned. Burns at a steady rate and not too fast. Grade: 4|
|Beech||Fagus||Beech has a high water content (approx. 90%) so only burns well when seasoned well. Not as good as Oak. Grade: 3|
|Birch||Betula||Birch is an excellent firewood and will burn unseasoned. However, it does burn very fast so is best mixed with slower burning wood such as Elm or Oak. Grade: 3-4|
|Cedar||Cedrus||A good firewood which burns well with a pleasant smell. Gives off a good, lasting heat. Doesn't spit too much and small pieces can be burned unseasoned. Grade: 2|
|Cherry||Prunus||Needs to be seasoned well. Burns well with a pleasant smell and without spitting. Grade: 2-3|
|Elm||Ulmus||A good firewood but due to its high water content of approximately 140% (more water than wood!) it must be seasoned very well. It may need assistance from another faster burning wood such as Birch to keep it burning well. However it gives off a good, lasting heat and burns very slowly. Dutch Elm Disease is producing a constant & plentiful supply of small dead hedgerow Elm trees of a small diameter. Larger pieces of wood will prove difficult to split. Grade: 2-3|
|Eucalyptus||Eucalyptus||Allow to season well since the wood is very wet (sappy) when fresh. Can be difficult to split due to stringy wood fibre. Best method is to slice into rings and allow to season during the summer, the rings will start to split themselves. Burns fast with a pleasant smell and without spitting. Grade: 2-3|
|Hawthorn||Crataegus||Good firewood. Burns well. Grade: 3-4|
|Hazel||Corylus||Excellent firewood. Allow to season. Burns fast but without spitting. Grade: 4|
|Holly||Ilex||Can be burnt green. A good firewood. Grade: 3|
|Hornbeam||Carpinus||Good firewood. Burns well. Grade: 3|
|Horse Chestnut||Aesculus||A low quality firewood. Grade: 2|
|Larch||Larix||Needs to be seasoned well. Spits excessively while it burns and forms an oily soot within chimney's. Grade: 1|
|Lime||Tilia||A low quality firewood. Grade: 2|
|Oak||Quercus||One of the best firewood's. When seasoned well, it gives off a good, lasting heat. Burns reasonably slowly. Grade: 4|
|Pear||Pyrus||Needs to be seasoned well. Burns well with a pleasant smell and without spitting. Grade: 3|
|Pine||Pinus||Needs to be seasoned well. Spits while it burns and forms an oily soot within chimney's. Grade: 1|
|Plane||Platanus||A usable firewood. Grade: 3|
|Poplar||Populus||Considered a poorer firewood (see comments below). Grade: 1|
|Rowan||Sorbus aucuparia||Good firewood. Burns well. Grade: 3|
|Spruce||Picea||A low quality firewood. Grade: 2|
|Sweet Chestnut||Castanea||Burns when seasoned but spits continuously and excessively. Not for use on an open fire and make sure wood-burning stoves have a good door catch! Grade: 1-2|
|Sycamore (Maples)||Acer pseudoplatanus||Good firewood. Burns well. Grade: 3|
|Walnut||Juglans||A low quality firewood. Grade: 2|
|Wellingtonia||Sequoiadendron||Poor for use as a firewood. Grade: 1|
|Willow||Salix||Willow has a high water content so only burns well when seasoned well. Grade: 2|
|Yew||Taxus||A usable firewood. Grade: 2-3|
Generally hardwoods are best for open fires because they tend not to spit excessively, however there are exceptions. Conifer wood tends to spit excessively when fresh, so is best used for sealed wood burning stoves, again there are exceptions. Many conifers also cause an oily, sticky 'soot' to form inside the chimney which can increase the risks of chimney fires. Once properly seasoned (see below) conifer wood can be successfully used on the open fire without excessive spitting. Ideally, conifer wood is best mixed with hardwood.
Wood to be seasoned should be cut to length (300mm or 10"-18"), split to size and stacked. The stack should be completely covered on the top to prevent rain wetting the wood but air must be allowed to reach the sides of the stack. Leave to season for at least 1 year (more if possible).
In simple terms, the word 'seasoned' means 'dry' and the term 'green' means 'freshly cut from living tree'.
It isn’t until you reach the truly isolated parts of the UK or wilder and woolier parts of the world that you realise just how hard it is to see our stars at night. Some interesting websites and resources are linked to at the end of this page.
The biggest obstacles are:
Bad weather: Enough said!
Pollution: This is worse when there is high pressure weather system sitting over the UK because the pollution is held down like a blanket over the ground. This is why you can often see a layer of yellow-brown air hanging over towns and cities. London sits in a ‘bowl’ so, from Primose Hill, the view over the Thames can look very dirty - the same happens in San Francisco when pollution is trapped against the surrounding hills. The effects get even worse in hot weather because the chemicals interact with the air. Equally, pollution can result from simple temperature inversion (cold air flowing off mountains over warmer city air that becomes trapped).
From time to time Europe can be the landing place for wind-borne dust and sand that has been whipped up by strong winds over the Sahara Desert in north Africa. A similar effect can be generated locally by ploughed fields or arid landscapes spinning dust high into the atmosphere. It is often the dust in our atmosphere that scatters light and gives us those magnificent red skies at night and in the early morning as sunlight has to travel through more atmosphere at shallow angles at sunrise and sunset. Beautiful, but another indication of pollution that astronomers dislike - beauty is in the eye of the beholder!
There have been several campaigns over the years and some useful web sites that can help you decide what is right for your own circumstances. Try the following: