Can the assignment "Depot Battalion" in Hart's Annual Army List be linked to a specific regimental assignment?

Upvote:5

A more readable copy of the 1887 Hart's List here

The reference being asked about is this mention of:

In summary, Brevet Col. Cardew's posting is to Staff Officer of Pensioners located at an appropriate Depot Battalion; in his case that of the Hounslow Regimental District - serving the 7th Royal Fusiliers (City of London Regiment) and the 57th 1st Battalion Duke of Cambridge's Own (Middlesex Regiment). He continues to draw his Captain's half-pay from the 9th Foot, to which he transferred from the 19th foot effective 23 October 1857.

Explanations:

Capt. h.p.
~~Designating that although commissioned as a Lt. Col., Lt. Col. Cardew has accepted his current posting at the pay grade of half-pay Captain.~~
This signifies that Col. Cardew has a substantive rank of Captain, half-pay. Here is the announcement from the Gazette Archive for 15 January 1884 (London) announcing the promotion to Colonel of Captain and Brevet Lieutenant-Colonel A. M. Cardew:
Depot Battalion
The 7th and 57th Regiments of Foot shared a depot battalion in London at this time, at Hounslow Barracks.

In 1875, the site was significantly expanded to create infantry barracks. Two years earlier a system of recruiting areas based on counties was instituted under the Cardwell Reforms and the barracks became the depot for the two battalions of the 7th Regiment of Foot. Following the Childers Reforms, the regiment evolved to become the Royal Fusiliers with its depot in the barracks in 1881. In 1875, the barracks also became the depot for the 57th (West Middlesex) Regiment of Foot and the 77th (East Middlesex) Regiment of Foot. Following the Childers Reforms, the 57th and 77th regiments amalgamated to form the Middlesex Regiment with its depot in the barracks in 1881. By 1884, the barracks had its own railway station on the newly created London Underground

However Staff Officers of Pensioners listing shows Lt. Col. Cardew assigned to the Regent's Park Barracks
S. O. of Pensioners
Refers to current appointment as a Staff Officer of Pensioners

Lt. Col. Ambrose Cardew's war service description is listed further down on that page as

The Gazette Archives for 8 October 1854 (London) and 15 December 1854 (London), respectively, expand on this:
7,57 LONDON
A Station reference to the Regimental District for the 7th Royal Fusiliers (City of London Regiment) and the 57th 1st Bn. Duke of Cambridge's Own (Middlesex Regiment) as noted here:

.

The Regimental Districts were formed as part of the Cardwell Reforms by the Regulation of the Forces Act 1871, abolishing General Service and providing for division of the country into 66 Brigade (Later Regimental) Districts.

Previously, soldiers had enlisted for General Service, and were liable to be drafted into any regiment regardless of their own preferences, another factor that had made service harsh and unpopular.

....

Under Cardwell's localisation scheme, the country was divided into 66 Brigade Districts (later renamed Regimental Districts), based on county boundaries and population density. All line infantry regiments would now consist of two battalions, sharing a depot and associated recruiting area. One battalion would serve overseas, while the other was stationed at home for training. The militia of that area then (usually) became the third battalion.

Lt. Col. Cardew was posted to the 7,57 London Regimental District as of publication of the 1887 Hart's List:

The 1871 edition of Hart's Army List shows that (then Captain) Cardew was recently appointed as a Staff Officer of Pensioners, on Oct. 1, 1870, and provides additional detail of the conditions for that service: