Article

Straits meteorology

From Munshipedia, the MBRAS digital historical encyclopedia

Straits meteorology

A.M. Skinner, writing in 1883 for the Journal of the Straits Branch of the Royal Asiatic Society, argued that rainfall in the Straits Settlements follows an approximately 10½-year periodic cycle synchronised with the sun-spot cycle, and that the severe drought of 1882–83 was a predictable manifestation of this recurrence. Drawing on the Colonial Government’s rainfall returns (1869–83) from nearly twenty stations along the West Coast of the Malay Peninsula, and on comparative data from 166 Dutch stations across the Eastern Archipelago, Skinner positioned the Straits as a natural laboratory for testing the then-emerging theory of solar-terrestrial periodicity.

Summary

Skinner opens by surveying the state of meteorological knowledge in the 1880s, reproducing at length a passage from the 1883 edition of the Encyclopædia Britannica that summarises the evidence linking sun-spot maxima to increased rainfall, higher river levels, greater cyclone frequency, and elevated temperature in the tropics. He extends this framework to the Straits context by examining the relationship between rainfall and two endemic diseases—cholera and beri-beri—citing official reports from Malacca and the Singapore Prison that correlate disease outbreaks with anomalous rainfall years. The cholera epidemic of 1882 in Malacca, for instance, coincided with a total annual rainfall of 66.19 inches, roughly thirty inches below the mean, while beri-beri mortality in the Singapore Prison peaked in 1879 (106 deaths) during a year of 118 inches of rain.

The article then turns to the question of deforestation and its effect on local rainfall, a matter of active administrative debate in the Straits. Skinner dismisses the hypothesis that timber clearance has materially reduced annual rainfall, arguing instead that the Dutch comparative data demonstrate that monsoon position—governed by whether a station lies north or south of the Equator—is the dominant factor in determining excess or deficit in any given year. He concedes, however, that deforestation and urbanisation have measurably raised local temperatures, citing Crawfurd’s 1855 observation that Singapore’s mean temperature had increased by 2.48 degrees since the settlement’s founding.

The core of Skinner’s argument is his demonstration that Singapore’s dry-day counts and annual rainfall totals exhibit a regular 10½-year oscillation. Using Wheatley’s earlier tables (Journal No. VII) extended to 1883, he identifies the driest years in successive periods as 1866–67 and 1876–77, and the wettest as 1869 and 1879–80. From this pattern he concludes that the 1882–83 drought was the expected closing of the solar period that began with the limited rainfall of 1872–73, and he goes so far as to predict an excess of rain in 1884–85 and a still greater excess in 1885–86.

Key Findings

  • The Straits Settlements maintained rainfall records from 1869 at nearly twenty stations along the West Coast of the Peninsula; the mean annual rainfall at Singapore was roughly 100 inches (p. 254).
  • The 1882 cholera epidemic in Malacca coincided with a total annual rainfall of 66.19 inches, approximately 30 inches below the average; during the five months of the epidemic (March–July) rainfall was less than a quarter of the annual total (p. 249).
  • Beri-beri deaths in the Singapore Prison peaked at 106 in 1879 (rainfall 118 inches) and fell to 22 in 1877 (rainfall 61 inches), suggesting a correlation with wet rather than dry years (p. 250).
  • Dutch observations from 166 stations in the Eastern Archipelago showed that in 1882, stations north of the Equator generally recorded below-average rainfall while those south of the Equator recorded above-average, confirming monsoon position as the governing factor (pp. 251–252).
  • Singapore’s dry-day totals for 1864–80 reveal a 10½-year periodic fluctuation: the driest years in successive periods were 1866–67 (23 dry days) and 1876–77 (11 dry days), while the wettest were 1869 (9 dry days) and 1879–80 (7–8 dry days) (pp. 253–254).
  • Annual rainfall totals confirmed the cycle: wet years recorded 123.24 inches (1870), 108.48 inches (1875), and 111.34 inches (1879–80), while dry years recorded 91.01 inches (1872–73), 61.19 inches (1877), and 73.33 inches (1882–83) (p. 254).

Conclusion

Skinner’s definitive claim is that the 1882–83 drought was not an anomaly but the predictable terminus of a solar-periodic cycle, and that meteorologists in the Straits can now hazard rainfall predictions on this basis. He acknowledges the insufficiency of the data for firm generalisation but insists that the regularity of the recurrence in the existing series is sufficient to warrant the expectation of above-average rainfall in 1884–86.

Context

  • Skinner was a colonial administrator in the Straits Settlements; the article reflects the practical administrative concern of the period—predicting drought and disease for agricultural and public-health planning—rather than a purely theoretical inquiry.
  • The primary sources consulted include the Colonial Government’s Rainfall Returns (1869–83), the Director of the Batavia Observatory’s comparative tables (fourth volume, 1882), Wheatley’s earlier rainfall paper (JSBRAS Journal No. VII, 1880), and official Malacca and Singapore Prison reports.

References