Early in 1826, at the age of 28, Charles Lyell began writing the first of a series of articles for J. G. Lockhart, the new editor of the Quarterly review. These articles gave him his first opportunity to express to the educated public his views on the state of science in general, and of geology in particular, in English society. According to the convention of the Quarterly, each article was nominally a review of one or more recently published works, but like other reviewers Lyell clearly chose them as ‘pegs’ on which to hang his own arguments. In content, the articles form a kind of ‘gradualistic’ series, rather like his own later interpretations of geological phenomena. At one end of the series (though published third) was an essay on the place of science in general in English university education. Another article (the first to appear in print) focused on some of the English institutions specifically devoted to science. Here there was a hint that the need for reform in the place of science in English society was not unrelated to a similar need for reform in Lyell's chosen branch of science. The next article enlarged on this hint by examining the publications of the Geological Society of London, on which Lyell had recently served as Secretary. This essay expressed for the first time in a general context Lyell's characteristic emphasis on the need for actualistic comparison between present and past. Finally, what he needed to complete the series was an article in which he could show in detail the positive explanatory advantages of following this method in geology. The ‘peg’ which he chose for this purpose was a single work, George Poulett Scrope's Memoir on the geology of central France.

In two recent articles by Russell and Whiteside, the reception of those particular conclusions of Kepler that have come to be called his laws of planetary motion has been subjected to the first research beyond the pioneering efforts of Delambre at the beginning of the nineteenth century. Independently conceived, and directed towards quite different ends, these two investigations overlapped in only one substantial area—their survey of citations of Kepler's second law by English astronomers between 1650 and 1670. Not surprisingly, they reached essentially identical conclusions about the situation in 1670. Finding ‘equant’ theories instead of the law of areas, wherever he looked, Russell qualified his general claim ‘that the importance of Kepler's ideas during the period [up to 1666] has been greatly underestimated’, to the extent of describing the history of the second law as ‘chequered’ and ‘complicated’. And Whiteside simply reported that Kepler's scheme for reckoning motion in the elliptical orbit ‘was seemingly firmly accepted by no one, and even its formal enunciation but rarely stated in the period’.

During the first half of the nineteenth century the Stirling brothers and John Ericsson made significant attempts to design hot air engines which could provide an economical alternative to high-pressure steam. They believed that it would be possible to gain fuel efficiencies superior to those obtained with steam by employing a heat exchanger within the air engine cycle, erroneously supposing that such a heat exchanger could eliminate the large loss of heat incurred in the condenser of the steam engine. The Stirling brothers called their heat exchanger an economizer because it prevented the waste of heat, but Ericsson coined the term regenerator because he imagined that the power of the heat (caloric) could actually be regenerated, i.e. re-used in the engine to generate mechanical work. Ericsson's term became commonly accepted, so that Stirling's economizer is now also referred to as a generator. These attempts to attain high horsepower outputs with hot air engines were abandoned after the dramatic failure of Ericsson's notorious paddle steamer in the early 1850s. Further ventures were aimed at the more limited goal of low horsepowers and generally ignored the regenerator principle.