Meteorological Observations

This simple glass receptacle, made from a funnel attached to a decanter, was devised by the Royal Society’s Operator, Henry Hunt (d.1713). It was intended to capture rainfall at Gresham College, the Society’s 17th century home.

Rainfall was recorded weekly and Hunt wrote a full account of his findings over the course of one year, 1695-96. This is now preserved in a volume of Royal Society archives dedicated to the study of meteorology.

Types of precipitation, such as snow, sleet, rain, drizzle and hail, are usually recorded in descriptive terms rather than measured by instruments.

Modern rain gauges differ from Henry Hunt's original instrument in that they can record and transmit precipitation data automatically.

Today, weather radars are used to determine the intensity and motion of precipitation.

This Met Office radar image captured storm Ciara as it battered Ireland and the United Kingdom on February 9th 2020 at 06.00 am.

Campbell-Stokes sunshine recorders are still widely used to quantify the number of hours of sunshine. Their design remains largely unchanged since the 19th century.
The glass ball focuses the rays of the Sun onto the cardboard card fixed to the back. On each card the Sun will burn a line, recording how sunny or cloudy a day was.

Howard's classification was immediately taken up by scientists and it also had a profound impact on art.

For instance, this painting of clouds and a rainbow over Hampstead Heath was one of a series of studies by John Constable (1776-1836). Shortly after Howard's classification circulated to the public, Constable decided to devote his considerable energies to an artistic record of the ever-changing sky.

Until remote-sensing instruments were developed in the 20th century, thermometers remained largely unchanged since the time of Daniel Gabriel Fahrenheit.

This mercury thermometer - included with the storm barometer designed by Robert FitzRoy FRS (1805-1865) - uses the Farhenheit scale, marking the freezing point of water at 32°F and summer heat at 75°F.

In order to shelter the thermometer and other weather observation instruments from the elements, a Stevenson screen is used.

The officer taking hourly observations on this photograph is one of the Women's Auxiliary Air Force who enlisted to carry out Met Office work during WW2 in Britain. Meteorological forecasting was crucial in supporting weather-dependent services such as the R.A.F., and in large-scale amphibious operations, such as D-Day in 1944.

In order to record temperature at different heights in the atmosphere, radiosondes are flown by weather balloons.

The sonde tracks temperature along with altitude, pressure, cosmic rays, relative humidity and wind (both wind speed and direction).

The first anemometer, an instrument to measure wind speed, is credited to the humanist scholar Leon Battista Alberti.

An architect, artist, cryptographer and cartographer, Alberti is reported to have designed the anemometer in the 1450s.

Leonardo da Vinci (1452-1519) famously improved on Alberti's design. In this manuscript, he notes in particular that a clock would be necessary to measure the speed per hour of the wind.

Still his design (top figure) included a scale carved into the curved frame. The piece of wood hanging pendulum-like at the front.

In this article published in the Transactions of the Royal Irish Academy, Thomas Romney Robinson (1792-1882) proposed the first major improvement to the anemometer since Alberti's original design.

In 1846, the Armagh astronomer designed an instrument which used four hemispherical cups rather than the single wood panels used previously.

Wind is experienced as the movement of air across the Earth’s surface and it is an important energy source. Wind can provide motive power for ships, but it can also be a hazard to navigation. Mapping the winds prevalent on the world's oceans was critical intelligence for fast and efficient trade.

Prevailing wind direction for each month was then calculated and plotted on this graph which divides the Atlantic Ocean into ten degree squares.