| 1845–1958 | Germany [earth sciences] | German naturalist and explorer Alexander von Humboldt lays the basis of modern geography with the publication of Kosmos/Cosmos, in which he arranges geographic knowledge in a systematic fashion. |
| 1878 | Netherlands [family planning] | Dutch doctor Aletta Jacobs opens the first contraceptive clinic in the world, in Amsterdam, the Netherlands. |
| 1878 | USA [fiction] | The US writer Henry James publishes his story ‘Daisy Miller’ and his novel The Europeans. |
| 1878 | UK [food and drink] | The British sugar manufacturer Henry Tate introduces sugar cubes. |
| 1878 | Denmark, Netherlands, USA [food and drink] | Swedish scientist Carl de Laval invents the centrifugal cream separator. It eliminates the need to leave milk in large pans to separate and leads to an expansion of the butter industry in Denmark, the Netherlands, and the USA. |
| 1878 | Germany [literature and language] | The German philosopher Friedrich Nietzsche publishes Menschliches, Allzumenschliches/Human, All Too Human. |
| 1878 | UK [manufacturing] | German-born British inventor Charles William Siemens invents the electric arc furnace, the first to use electricity to make steel. |
| 1878 | UK [opera] | The comic opera HMS Pinafore, or the Lass Who Loved a Sailor, by the English writer William Schwenk Gilbert and the English composer Arthur Seymour Sullivan, is first performed at the Opera Comique in London, England. |
| 1878 | France [sculpture] | The French artist Auguste Rodin sculpts Walking Man. |
| 1878 | USA [technology] | The Remington Model 2 typewriter is introduced in the USA. It is the first typewriter to have a shift key to write both upper and lower case letters; earlier typewriters had only capitals. |
| 1878 | UK [Christianity] | The English evangelist leader William Booth begins his ‘Christian Mission’ in the East End in London, England. This forms the basis of the Salvation Army. |
| 9 January 1878 | Italy [political events] | Humbert I succeeds as king of Italy on the death of Victor Emmanuel II. |
| 28 January 1878 | USA [telephone services] | The first commercial telephone exchange opens in New Haven, Connecticut; it has 21 subscribers. The following month the first telephone directory is published by the New Haven Telephone Co. with 50 subscribers listed. |
| 7 February 1878 | Papal States [political events] | Cardinal Joachim Pecci is elected as Pope Leo XIII. |
| 3 March 1878 | Russian Empire, Ottoman Empire, Balkans [treaties] | By the preliminary Treaty of San Stefano ending the Russo-Ottoman War over the Balkans, Montenegro is to be enlarged with the port of Antivari; Romania, Montenegro, and Serbia are to be independent; reforms are to be undertaken in Bosnia and Herzegovina; Bulgaria is to be enlarged with a seaboard on the Aegean and most of Macedonia; and Russia is to receive the fortified cities of Ardahan, Kars, and Batum in eastern Anatolia, while the Ottoman Empire is to pay Russia a huge indemnity. |
| 21 March 1878 | USA [births and deaths] | Jack Johnson, US boxer and the first black person to win the world heavyweight boxing championship (1908–15), born in Galveston, Texas (–1946). |
| 5 June 1878 | Mexico [births and deaths] | Francisco ‘Pancho’ Villa, Mexican revolutionary who fights against the regimes of Porfirio Díaz and Victoriano Huerto, born in Hacienda de Rio Grande, Mexico (–1923). |
| 13 July 1878 | Austria-Hungary, Ottoman Empire, Romania, Russian Empire, Montenegro, Serbia, UK, Cyprus [treaties] | By the Treaty of Berlin, Bulgaria is split into (a) autonomous Bulgaria, north of the Balkans, (b) Eastern Rumelia with a special organization under the Ottoman Empire, and (c) Macedonia, where reforms are to be undertaken; Austria-Hungary is given a mandate to occupy Bosnia and Herzegovina; Romania is warded the region of Dobrudja but has to hand over South Bessarabia to Russia; Montenegro is given the port of Antivari; Montenegro, Romania, and Serbia become independent states; Russia receives the towns of Batum, Kars, and Ardaham; and the British occupation of Cyprus is confirmed. Italian and Greek demands are shelved, while promises for reforms in Macedonia and Asia Minor lead to agitation. |
| 3 September 1878 | UK [transport disasters] | Over 600 people are killed in England when the pleasure steamer Princess Alice sinks in the Thames. |
| 18 October 1878 | Germany [legislation] | An anti-Socialist law in Germany prohibits public meetings, publications, and collections, thus driving socialism underground. |
| 30 November 1878 | UK [television] | English chemist and physicist William Crookes describes an early form of the cathode-ray tube, now known as Crooke's tube, to the Royal Society. It is a forerunner of the television tube. |
