The mobility of the British foot artillery compared with horse artillery was discussed in correspondence between Congreve (who had commanded the artillery under the Duke of York in the Low Countries, and was father of the developer of the Congreve rocket) and the Master General of the Ordnance in the 1790s (Royal Artillery Museum Archive - RA 20 Manuscript Book of Collected Military Papers on Artillery Matters, Volume II ). Congreve wrote in March 1795:

“In the Month of August 1793 I had the Honour to be ordered by His Royal Highness the Duke of York to march with two Royal Howitzers and two long six Pounders to support an advanced Corps of the Allied Army near Orchies.
With each Howitzer I had a new pattern wagon drawn by four Horses, the Howitzer being drawn by the same number with 74 Rounds of Ammunition and Eight Artillery Men carried for the Service of each. The long six Pounders of 12 Cwt carried five Artillery Men and 52 Rounds of Ammunition and were each drawn by six Horses.

I make no doubt but that the Cases just stated are sufficient proofs of the utility of General Desagulier's System of Field Carriages, and of the possibility of the Corps of Foot Artillery being capable of moving fast enough with 5½ Inch Howitzers, long 3 Pounders and even long 6 Pounders of 12 Cwt for the Service of Cavalry, and at nearly one third the Expense of the Duke of Richmond's Corps of Horse Artillery, and without being incumbered with a multitude of Saddle Horses which in Action must be exposed to the Enemy's Shot and which at all times impede an Army by lengthening the Line of march, requiring a great addition of Forage, and large supplies of Horses to replace the sick ones which are always numerous towards the latter End of a Campaign….The Corps of Horse Artillery however may be well employed with such pieces as are too heavy to admit Men to ride upon their Carriages

I beg to observe that although a detachment of Foot Artillery cannot ride upon the Carriage of a Medium 12 Pdr or 8 Inch Howitzer, yet the Men may accompany the Pieces on common Ordnance Waggons at the Rate of 6 Miles an hour, each carrying ten Men with Six Horses and three Postilions, by which method of travelling they can keep up with the Pieces of Ordnance and the Men will be more fit for the Service of the Ordnance than if they had rode on Horse-back, as they may even sleep during their journey". (pp. 286-90)

On 11 February 1797, he wrote again "As Superintendant of Military Machines, it is my Duty to remonstrate against the introduction of the Field Carriage which will not admit of the Artillery Men riding upon it” and enclosed a copy of a Certificate from Colonel St Leger (Deputy Adjutant General of the British Troops under the Duke’s command) dated 10 December 1793 that "It is with the sincerest satisfaction that on the attack made by the French on our out posts at Orchies in the month of August last, I saw the Artillery under your command move a considerable deal quicker than the Hanoverian flying Artillery, gain the position intended, and fire upon the enemy before the Hanoverians were prepared, tho' they had quitted Orchies at the same time that you had done." (pp. 270-1)

Congreve was no doubt swimming against the tide of modern theories and developments, but his comments, based on his experience, are still interesting.