Any ideas on these 2 photos please?

[bobblehat]

Any suggestions re 2 photos appreciated.
First is a British cavalry officer-cant quite make out the sabretache badge-Lancers perhaps?On the collar it looks like a Victoria crown but not sure and cant see anything on the foreign service helmet.Photo taken in 1878.
Second one is of a soldier with grenade badge on collar-possibly engineer/artillery?The photographer is based in Valetta Malta so possibly Malta Artillery rather than a British soldier visiting?