JMW Turner was famous for his use of swirling colours and for the dynamic nature of his work.
This is definitely true of this painting, where swirls of steam and a rushing sky help to convey the impression of a train in dynamic motion.
Rain Steam Speed depicts the Great Western Railway, which, after the innovations of the Bristolian engineer Kingdom Brunel, was one of the most lauded developments of the industrial age in Britain.
The Great Western Railway is, in fact, still in existence in the UK though trains have now been modernised and no longer use steam, and the name has been shortened to GWR.
In Rain Steam Speed, we can see echoes of other works by Turner, such as his depictions of storms at sea. The painting 'Snow Storm', for example, which he painted over 20 years earlier in 1822-3 depicts a steam boat caught in a storm out to sea.
Again, we see the twin themes of nature's power and human industry that are also at work in Rain Steam Speed.
The dramatic sea spray and waves surrounding the boat in Snow Storm might be compared to the dramatic steam and rain surrounding the train in Great Western Railway.
One interesting thing about Great Western Railway, though, is the way in which the steam and the rain become blended and indistinguishable. We cannot see which vapour is produced by the train and which is produced by nature itself.
This is helped by Turner's characteristic way of working with oils: he is well known for swirling and blending colours together to create a unified, bold look.
Perhaps, here this is something that goes beyond a mere stylistic aspect of Turner's work, however, Perhaps, by blending steam and rain in this way, Turner is commenting on the way in which human engineering can become one with nature - it can add to its power and its strength.