The judgment of the court was delivered by

KUMARAYYA, C.J. - This tax revision case raises a short point as to whether "electric detonators" manufactured by the assessee, the Indian Detonators Ltd. are "electrical goods" falling within entry 37 of Schedule I to the Andhra Pradesh General Sales Tax Act, 1937, so that they may be subjected to sales tax at the rate of 7 per cent. A "detonator" is an explosive accessory for initiating high explosives. It is used for blasting purposes and is issued only against special licence to be obtained by persons concerned with blasting or mining operations. It contains chemical composition inside a metallic tube, whether aluminium or copper, which is closed at one end. In this tube are compressed two charges of initiating explosives successively. One is base charge and the other is priming charge. The chemical mixture in each of them is somewhat different from the other. The tube with explosives thus compressed thereinto forms a "detonator". In order that this detonator may function, it is necessary that the explosive chemicals therein should be ignited. This ignition is effected in more than one way. One of the methods of igniting it is to provide a train of black powder called "safety fuse" which would carry a flame from a point sufficiently away from the explosives to the initiating explosives. This method, under certain circumstances, especially in an atmosphere of explosive mixture of gases, proves hazardous. The detonators which are to be used under such conditions are provided with facilities to ignite them by passing electric current and they are on that basis called "electric detonators", the first of the kind being ordinary detonators. The assessee-company manufactures both the types of detonators but sets a very high value, 7 to 8 times more than ordinary detonators, on electric detonators probably due to a sort of monopoly in some measure that it enjoys. The electric detonators are provided with two metal strips which are held together and separated from each other by means of insulating material. To one pair of ends of these strips are soldered leading wires. The other pair of ends are joined together by means of a high resistance nichrome wire. This wire is called "bridge wire". The bridge wire is surrounded by a mixture of charcoal and other ingredients. On passing the electric current through the leading wire and the bridge wire, the bridge wire glows and ignites the mixture of chemicals giving a hot flash on ignition. This hot flash is conveyed to the priming charge, the ignition of which in turn explodes the base charge. The shock energy available in the detonation of these two charges is conveyed to the explosive cartridge within which is buried the detonator. This causes the explosion that is utilized in commercial blasting practices. That is how the nature and the kind of detonator manufactured by the assessee has been described by Shri V. Y. Tambe, an expert whose opinion forms part of the record of this case. Practically, there is no difference between ordinary and electric detonators so far as detonator or explosive portion is concerned. The combination of chemicals compressed in the metallic casting in both the kinds of detonators is essentially the same. If at all there is any difference between the two kinds of detonators, it is in the method of setting off the detonators. While for ignition of the priming charge flame is carried through the safety fuse in the ordinary detonators, in the case of electric detonator the flame is produced from passing electric current through its fuse end. The difference in the mode of ignition in the two types of detonators in no way affects the explosive potency of the chemicals therein. In other words, the efficiency of the detonator is unaffected and would be the same, whether it is ignited by electric current or ordinary flame because the explosion is caused by the chemicals whether the fuse is ignited by means of mechan