Berliner Gramophone formulations remained the standard disc record material until the first vinyl records – initially made only for radio use and other special applications – were introduced in the 1930s. Beginning in 1896, Berliner's gramophones were made by Philadelphia-based machinist Eldridge Johnson, who added a spring motor to drive the previously hand-rotated turntable. Berliner also opened an office in New York City, staffed by Frank Seaman and O. D. LaDow and organized as the National Gramophone Company. Master recordings were made onto zinc plates, which were then electroplated and a negative-image "mother" made from them to stamp discs. A major reversal
Polymer (library) classes. Custom element definition comprises CSS style, HTML template of the element's local DOM, element properties, lifecycle callbacks and JavaScript methods: import {PolymerElement, html} from '@polymer/polymer/polymer-element.js' class HelloElement extends PolymerElement { static get template() { return html` static get properties() { /* Custom methods */ window.customElements.define(HelloElement.is, HelloElement); The element defined above can be used in HTML code: <hello-element name="World"></hello-element> Polymer (library) Polymer is an open-source JavaScript library for building web applications using polymer Web Components. The library is being developed by Google developers and contributors on GitHub. Modern design principles are implemented as a separate project using Google's Material Design