Answer:
improvement of the steam engine
Step-by-step explanation:
The Second Industrial Revolution is what is called the group of interrelated socio-economic transformations that occurred approximately between 1850-1870 until 1914. During this period the changes underwent a strong acceleration. The process of industrialization changed its nature and economic growth varied from model. Technical changes continued to occupy a central position, together with technical innovations concentrated essentially in new sources of energy such as gas, oil or electricity; new materials and new transport systems (airplane and automobile) and communication (telephone and radio) induced chain transformations that affected the work factor and the educational and scientific system; to the size and management of the companies, to the form of organization of the work, to the consumption, until ending also in the policy.