that Siam would gift elephants to be beasts of burden, in which President Lincoln politely declined, stating that "steam has been our best and most efficient agent of transportation in internal commerce". Demography The Siamese effective manpower had been in decline since the late Ayutthaya period. The Fall of Ayutthaya in 1767 was the final blow as most Siamese were either deported to Burma or perished in war. The manpower shortage of Siam was exemplified during the Nine Armies' War in 1785, in which Burma sent the total number of 144,000 men to invade Siam who managed to only gather 70,000 men for defenses. D.E. Malloch, who accompanied Henry Burney to Bangkok in 1826, noted that Siam was thinly populated and the Siamese lands could support about twice the size of its population. Manpower management Manpower had been a scarce resource during the early Bangkok period. The Department of Conscription or Registers, the Krom Suratsawadi (), was responsible for the record-keeping of able-bodied men eligible for corvée and wars. Krom Suratsawadi recorded the Hangwow registers () – a list of available Phrai commoners and That slaves to be drafted into services. However, pre-modern Siam did not maintain an accurate census of its population. The survey by the court focused on the recruitment of capable manpower not for statistical intelligence. Only able-bodied men were counted on that purpose, excluding women and children and those who had escaped from authority to live in the wilderness of jungles. The authority of Siamese government extended only to the towns and riverine agricultural lands. Most of the pre-modern Siamese lands were dense tropical jungles roamed by wild animals. Leaving the town for jungles was the most effective way to avoid the corvée obligations for Siamese men. The Siamese court devised the method of Sak Lek () to strictly control the available manpower. The man would be branded with the heated iron cast to create an imprinting tattoo on the back of his hand in the symbol of his responsible department. The Sak Lek enabled prompt identification and prevented the Phrai from escaping government duties. The Sak Lek was traditionally conducted once in a generation, usually once per reign and within Central Siam. King Rama III ordered the Sak Lek of Laos in 1824, which became one of the preceding events of the Anouvong's Lao Rebellion in 1827. Sak Lek of Southern Siamese people were conducted