Complex sentence: MacLaurin enlisted in the New South Wales Scottish Rifles while still at university and was commissioned as a Second Lieutenant in 1899 and was promoted to Lieutenant in 1900, Captain in 1903 and Major in 1908.
Split into simpler sentences: MacLaurin enlisted in the New South Wales Scottish Rifles while still at university and was commissioned as a Second Lieutenant in 1899. He was promoted to Lieutenant in 1900, Captain in 1903 and Major in 1908.