William Moorcroft was an explorer, doctor, veterinary surgeon, and Superintendent of the East India Company's horse stud. He had an interest in expanding trade in Central Asia, where he thought the Russian traders were already active. In 1820, Moorcroft, George Trebeck and George Guthrie left India for Bukhara to buy Turkoman horses and reached Bukhara in 1825. However, all three died of fever on the return journey. His travels were published in 1841. Charles Masson, formerly of the East India Company, resided in Baluchistan, Afghanistan and the Punjab between 1826 and 1838 and published his travels. In September 1829, Lieutenant Arthur Conolly of the East India Company travelled from St. Petersburg, Russia to the Caspian desert, to Kir (northern Iran), was detained in Astrabad (northern Iran) as a Russian spy, then travelled with a caravan of pilgrims to Meshed, marched with the Afghan army from there to Herat, then traveled to Kandahar, to Quetta, then across the Indian desert to the British frontier in January 1831. He published his travels in 1834. However, after 1830, Britain's commercial and diplomatic interest to the north-west would eventually become formidable. In 1831, Captain Alexander Burnes and Colonel Henry Pottinger's surveys of the Indus river would prepare the way for a future assault on the Sind to clear a path towards Central Asia. Burnes embarked on a dangerous 12-month journey beginning in 1831 into Afghanistan and through the Hindu Kush to Bukhara, returning in 1832. Burnes, a Christian travelling through a Muslim country was one of the first to study Afghanistan for British Intelligence and upon his return, he published his book, "Travels To Bukhara", which became an overnight success in 1834. Between 1832 and 1834, Britain attempted to negotiate trade agreements with Ranjit Singh, ruler of the Sikh empire, and the Amirs of Sindh. However, these attempts were unsuccessful.