Opium Weights from Northern Siam & Laos

April 1st, 2015

Over the past year or so we have been introducing more opium weights from Northern Siam and Laos to our collection. These weights are quite distinct from the better known weights cast in Burma that fall into mainly two categories- the beast and bird weights of various incarnations tied to the change of monarch. Weights from Siam and Laos include the elephant, toe, and hamsa and later, certain animals from the oriental solar zodiac including the horse, rooster, tiger, bull, goat, snake, rabbit, monkey, dog, and pig. The bronze is generally of high quality with a dark patina varying from grey to chocolate brown. These weights make a nice addition to Burmese weights for the collector. In our experience, they are found in fewer numbers than Burmese weights.

Opium Weights from Siam and Laos


It is reported in the Annals of Chiangmai that in 1460 AD, the Siamese adopted the Chinese word peng to refer to a particular mass and today is used to refer to the bronze animal weights in general. In 1558 AD, Chiang Mai, the capital of the La-Na Kingdom, was sacked by the Burmese who destroyed the weights and measures system, and along with it, the currency of the kakim silver ingot. The Burmese introduced their own floral ingot as well its own standardization of weights and measures. It is likely that elephant weights were cast at this time and continued to be produced after the Burmese lost control in the second half of the 18th century. Following the departure of the Burmese, other animal shaped figurines made their appearance and it has been suggested that other than serve as weights, they were used as currency. In 1858 Siam began producing machine made coins eliminating the need for bronze figurines to serve as currency. Even so, animal shaped figurines continued to be cast. In Earth to Heaven, Donald and Joan gear suggest that the elephant weights originated in northern Siam rather than Laos.

Elephant Opium Weights
Elephant Opium Weights from Siam & Laos

The bases of Siamese weights were mostly octagonal and occasionally ellipse. The sides are commonly stepped and often vertically striated. Astrologers of the time were known to keep a set of these figurines used in predicting future outcomes. In general, elephant shaped weights have a sign marked on the base resembling the blades of a windmill. Occasionally, other animal shapes were also marked with a sign on the base, mostly in the form of radiating stars with 4,5,6,7 or 8 rays.

Bronze elephant weights from Siam (and Laos) were often used to weigh silver bullion, opium (which was widely used at the time), medicines, as well as a form of money. Mostly, the mass varied from 5 to 300 grams. A common feature of Siamese weights is that a small lump of bronze has been removed from the base to adjust the weight – evidence that the figurines were in fact used to weigh materials. Conversely, some weights appear to have been adjusted up in weight with a lump of solder between the legs. Early French travelers to Siam were suspicious that Siamese merchants kept two sets of weights of indistinguishable appearance – one slightly heavier set that were used when buying goods, and a lighter set to be used when selling. It’s clear on inspection of surviving examples that Siamese weights tend to be less accurate than Burmese weights.

Bronze Animal Opium Weights from the Solar Zodiac
Bronze Animal Opium Weights from the Solar Zodiac


Despite our efforts, we have not found any substantial written material specifically about opium weight production in Laos. During regular visits to Laos over the past 14 years we have seen and acquired a number of opium weights in the form of the elephant, lion-beast, the various animals from the solar zodiac, as well as some rarely seen forms such as the stag.   The Gears’ deduce in their guidebook, Earth to Heaven, that elephant weights, while not originating in Laos (as popularly thought), were cast there along with other animal forms. A  Laotian friend and enthusiastic antique collector was confident in telling us that opium weights were cast in the 19th century (and probably much earlier) in Phongsali, a town amongst the mountains in the far north of the country. She suggested that the weights were commonly used to weigh opium cultivated by the Hmong hill tribe people, as well as other precious items. Along with our friends who collect opium weights, we are often unable to distinguish between weights cast in Laos and those cast in Siam and so tend to group them together. Visit our opium weight collection.