Chap­ter I — The mem­oir of Fleem­ing Jenkin opens with a per­son­al rec­ol­lec­tion by Sir William Thom­son, who lat­er became Lord Kelvin, describ­ing his first encounter with Jenkin in 1859. Jenkin was intro­duced to Thom­son through Lewis Gor­don, already active in the emerg­ing field of sub­ma­rine teleg­ra­phy. At the time, Thom­son was deeply engaged in test­ing under­sea cables, and Jenkin had been rec­om­mend­ed to observe the process due to his tech­ni­cal apti­tude. Their meet­ing led to a pro­fes­sion­al rela­tion­ship root­ed in mutu­al respect for pre­ci­sion and a shared inter­est in improv­ing long-dis­tance elec­tri­cal com­mu­ni­ca­tion.

Jenkin impressed Thom­son with his detailed atten­tion and ana­lyt­i­cal approach, char­ac­ter­is­tics that would define his career. Their ear­ly con­ver­sa­tions, ini­tial­ly focused on cable con­duc­tiv­i­ty and insu­la­tion, soon evolved into broad­er dis­cus­sions about physics and engi­neer­ing the­o­ry. This intel­lec­tu­al part­ner­ship extend­ed beyond casu­al exchange, becom­ing a con­sis­tent and thought­ful cor­re­spon­dence. Their col­lab­o­ra­tion reflect­ed a deep­er pur­pose: under­stand­ing how to mea­sure and man­age sig­nal strength through long sub­ma­rine cables effec­tive­ly. Togeth­er, they explored the vari­ables that influ­enced elec­tri­cal resis­tance and sig­nal delay, set­ting the stage for stan­dard­ized approach­es in cable teleg­ra­phy.

A notable con­tri­bu­tion by Jenkin involved the appli­ca­tion of absolute mea­sure­ment sys­tems to the analy­sis of elec­tri­cal com­po­nents. He adopt­ed prac­tices devel­oped by Ger­man sci­en­tists like Gauss and Weber, who had pio­neered rig­or­ous quan­ti­ta­tive meth­ods. Jenkin applied these prin­ci­ples specif­i­cal­ly to sub­ma­rine cables, ensur­ing that every mate­r­i­al was test­ed with sci­en­tif­ic accu­ra­cy. His abil­i­ty to merge empir­i­cal data with the­o­ret­i­cal knowl­edge helped sta­bi­lize and improve the qual­i­ty of transocean­ic com­mu­ni­ca­tion. These efforts advanced not only the cable indus­try but also the broad­er field of elec­tri­cal mea­sure­ment. In doing so, he helped shift engi­neer­ing from a craft-based dis­ci­pline to a sci­ence ground­ed in repeat­able pre­ci­sion.

Among his most rec­og­nized achieve­ments was his study of cable insu­la­tion, par­tic­u­lar­ly focus­ing on gut­ta-per­cha, the stan­dard insu­lat­ing mate­r­i­al of the time. Jenkin doc­u­ment­ed its resis­tive qual­i­ties with metic­u­lous care, pro­duc­ing the first known data on its elec­tri­cal prop­er­ties. This infor­ma­tion proved cru­cial for opti­miz­ing the mate­ri­als used in under­sea cabling. His find­ings were pub­lished in respect­ed ref­er­ence works, includ­ing the Ency­clopae­dia Bri­tan­ni­ca, high­light­ing both their impor­tance and his grow­ing author­i­ty in the field. Engi­neers relied on this data when con­struct­ing more effi­cient and reli­able cable sys­tems. It marked a turn­ing point in apply­ing mate­r­i­al sci­ence to elec­tri­cal infra­struc­ture.

Thom­son also ref­er­enced Jenk­in’s pub­lished paper in the Trans­ac­tions of the Roy­al Soci­ety, which detailed exper­i­ments on sig­nal behav­ior with­in sub­ma­rine lines. This research exam­ined how elec­tri­cal puls­es weak­ened or changed as they trav­eled through extend­ed lengths of insu­lat­ed wire. Although the sec­ond por­tion of that study, which was expect­ed to explore elec­tro­sta­t­ic effects in more detail, was nev­er released, the ini­tial find­ings still had sig­nif­i­cant influ­ence. They touched on the spe­cif­ic induc­tive capac­i­ty of insu­lat­ing mate­ri­als, a sub­ject that would gain impor­tance as the elec­tri­cal sci­ences matured. These ear­ly insights fore­shad­owed more advanced the­o­ries in dielec­tric behav­ior and telecom­mu­ni­ca­tion design.

Jenk­in’s work con­tin­ued to inspire devel­op­ments in stan­dard­ized elec­tri­cal mea­sure­ment, which would even­tu­al­ly be cod­i­fied at an inter­na­tion­al lev­el. His approach laid the foun­da­tion for con­sis­ten­cy in test­ing and bench­mark­ing elec­tri­cal sys­tems, ensur­ing engi­neers around the world could com­mu­ni­cate and com­pare results. By the time of the Elec­tri­cal Con­gress held in Paris in the 1880s, many of the tech­niques he had pro­mot­ed had become uni­ver­sal­ly accept­ed. His influ­ence extend­ed well beyond the lab­o­ra­to­ries where he worked. It shaped pol­i­cy, edu­ca­tion, and indus­try stan­dards across con­ti­nents. In many ways, Jenkin helped write the rule­book for mod­ern elec­tri­cal engi­neer­ing.

His sto­ry, as recalled in this chap­ter, is not only one of inven­tion but of dis­ci­pline and fore­sight. Jenk­in’s method­i­cal pur­suit of exact mea­sure­ment brought order to a chaot­ic field still in its infan­cy. He showed that under­stand­ing the invis­i­ble forces behind elec­tri­cal trans­mis­sion required both cre­ativ­i­ty and rig­or. His col­lab­o­ra­tion with Thom­son and oth­ers under­scored the pow­er of shared inquiry. Through their com­bined efforts, the world moved clos­er to depend­able, long-dis­tance com­mu­ni­ca­tion. And in that progress, Jenkin’s lega­cy con­tin­ues to res­onate in every cable laid and every sig­nal trans­mit­ted.