 Three of his most enduring books were written over the next decade, "The Young Fur Traders", "Ungava", "The Hudson Bay Company", and were based on his experiences with the H.B.C.  In this period he also wrote "The Coral island" and "Martin Rattler", both of these taking place in places never visited by Ballantyne.  Having been chided for small mistakes he made in these books, he resolved always to visit the places he wrote about.  With these books he became known as a great master of literature intended for teenagers.  He researched the Cornish Mines, the London Fire Brigade, the Postal Service, the Railways, the laying down of submarine telegraph cables, the construction of light-houses, the light-ship service, the life-boat service, South Africa, Norway, the North Sea fishing fleet, ballooning, deep-sea diving, Algiers, and many more, experiencing the lives of the men and women in these settings by living with them for weeks and months at a time, and he lived as they lived.