Newall was born in Dundee. In 1840, he took out a patent on the manufacture of wire ropes and in partnership with Messrs. Liddell and Gordon, set up his headquarters at Gateshead. A world-wide industry of wire-drawing resulted. The submarine telegraph cable received its definitive form through Newall's initiative, involving the use of gutta percha surrounded by strong wires. The first successful Dover-Calais cable on 25 September 1851, was made in Newall's works. In 1853, he invented the brake-drum and cone for laying cable in deep seas. Half of the first Atlantic cable was manufactured at his works. The last submarine line laid by him personally was that connecting Ringkjobing in Denmark with Newbiggin in Northumberland in 1868.
Newall was interested in astronomy, and his giant 25 inch telescope was set up in the garden at Ferndene, his Gateshead residence in 1871. Newall had married the youngest daughter of Hugh Lee Pattinson (q.v.), who was also a keen amateur astronomer and owned many telescopes, the biggest of which was a 7.5 inch refractor made by Thomas Cooke. This was the instrument loaned to Charles Piazzi Smyth (1819-1900), to be used on his 1856 expedition to Teneriffe aboard Robert Stephenson's yacht Titania.
Newall's famous telescope was removed to Cambridge University in the autumn of 1891, with Newall as observer but by the end of the 1950s, the telescope had fallen into disuse and the university offered to donate it to any observatory wishing to accept it. It was eventually shipped free of charge to Athens and since November 1958, has been at the Penteli Observatory just north of the city. Now the expanding city has engulfed the observatory, and Newall's great telescope is used for training purposes and also by the public and the Greek Amateur Astronomers' Club.