Reviewing Fleeming Jenkin's Electricity and Magnetism in Nature in 1873 an anonymous reviewer (probably James Clerk Maxwell) remarked that "at the present time there are two sciences of electricity--one that of the lecture-room and the popular treatise; the other that of the testing-office and the engineer's specifications." In this paper I want to look behind Maxwell's remark and examine the relationship between the "two sciences" of electricity during the third quarter or so of the 19th century. In particular I want to look at them in terms of their instrumental technologies. How did apparatus travel between the lecture-room or exhibition-hall and the testing-office or the laboratory? How did skills cross between these different spaces? How did the earlier Victorian culture of electricity as "entertainment and edification" become transformed into late 19th century metrological culture? How did these cultures overlap and how did they differ?