The Alder (Alnus glutinosa) is not so handsome a tree as the birch, and the timber not so useful. It is a native of most parts of Europe. It thrives best in marshy situations, and next to lakes and rivers, where it is more a large shrub than a tree. Its shade improves rather than injures the grass.
Alder bark contains much tannin, and the young shoots dye a yellow or cinnamon colour. The catkins dye green. The twigs of the alder are brittle, and so is the stem when green. In that state it is more easily worked than any other timber.
When much larger, the timber of one of the varieties (there are several) is red, amd often so finely streaked that it is called Scotch mahogany, and furniture is made of it. That which is got out of the bogs in an undecayed state has the colour but not the consistency of ebony. Of birch or holly, which are very white, of juniper, which has a slight cinnamon tinge, and of the bog alder or bog oak, both of which are black, the coopers in the north of Scotland form variegated cups, some of which are very handsome.
In moist situations alder does well for foundation piles. From the ease with which it can be perforated when green, and from its not being liable to split, it is well adapted for wooden pipes.
On the banks of the Mole, in Surrey, the alder grows very well. It adds great beauty to the landscape in the neighbourhood of Dorking and Esher.
summarised from "The Library of Entertaining Knowledge - Timber trees" (1829), pub. Charles Knight, Pall Mall.
OTHER USES OF ALDER (Miles Hadfield, writing in 1950): -
Alder was used until fairly recently for making the soles of clogs. Once dried it is water-resistant and does not split when nailed near the edges. It is a poor firewood. Alder charcoal was an important ingredient of black gunpowder.