Oven gas stove included the AGA cooker invented in 1922 by Gustaf Dalén. The first electric ovens were invented in the very late 19th century, however, like many electrical inventions destined for commercial use, mass ownership of electrical ovens could not be a reality until better and more efficient use of electricity was available. More recently, ovens have become slightly more high-tech in terms of cooking strategy. The microwave as a cooking tool was discovered by Percy Spencer in 1946, and with the help from engineers, the microwave oven was patented. The microwave oven uses microwave radiation to excite the molecules
Spencer Combe as shown in the Percy window in the chapel of Petworth House and as quartered by Cary, Viscount Falkland. The American genealogist Douglas Richardson suggests however that Sir Robert Spencer was in fact the son and heir of John Spencer, Esquire, MP for Dorset, of Frampton in Dorset, Ashbury in Devon and Brompton Ralph in Somerset, by his wife Jone. The arms given by Pole for Spencer of Spencer Combe, are: "Argent, on a bend sable two pairs of keys or", and are shown quartered by Prideaux on the monument in Farway Church, Devon, to Sir Edmund Prideaux, 1st Baronet