Fear & British press during the Napoleonic Wars

That's a good article

I wonder why there is no mention of the Fencible regiments, raised for home service, that supplemented the regular army c.1793-1804

That's a good question. I think the Great Fear had several significant impacts on the British Army.

1. The great expansion of the militiat system, including the fencibles, created a ready pool of, at least partially trained, recruits for the army during the key years of the Peninsular War.

2. It increased the emphasis on the need for a much larger force of light infantry, becaues of the enclosed nature of the country in along the English coast. Many officers of the period comment on this inlcuding Money, MacDonald, Cornwallis and others.

3. With the expansion of the militia came the need to arm them, which led to the expansion of the British aramements industry. This eventually led to a great surplus of arms which were sent to other belligerents in the coalition.

In my opinion the Great Fear was overblown and Pitt himself thought so as well, at least according to MacDonald, but the impacts were far reaching. According to MacDonald in his relatively obscure work "Instructions for the Conduct of Infantry on Actual Service" relates Pitt's statement at a dinner party in a rather lengthy footnote that runs over the course of several pages (p. xxviii in the preface of the edition I have):

"On the subject of invasion he spoke with a rather guarded caution; and his sentiments were elicited rather than volunteered. He deemed the attempt more possible, than probable, though in a public capacity, he supported other opinions, with a view of animating the Nation to make the requisite preparations for meeting the contenst."

Sir Sidney Smith and General Dundas were also present at the dinner.