JUDGMENT

Costello, J. - These two patent appeals are concerned with two sets of proceedings which were tried and determined by Mr. Justice Ameer Ali more or less together. They were not formally consolidated, and indeed they could not have been, because the parties in the one were not exactly the same as the parties in the other. But the facts in issue and the points of law arising in each of them were, to a large extent, identical. Appeal No. 62 of 1937 arises out of Suit No. 2203 of 1935 and in it the Plaintiffs (as set out in the cause title) were: Ernest Bruno Nier, Ida Ella Adolph, Richard Woldemar Nier, Martha Helene Pross and Johannes Kurt Nier, forming a partnership firm constituted under the laws of the German Reich and trading under the name and style of Hermann Nier, having their principal office and place of business in Beirfeld (Saxonia) in Germany, and all residing in Beirfeld aforesaid. They sue by their constituted attorney in India, Hanns George Fischer of F. Racek & Co., carrying on business at Lohar Chawl, Lohar Street, in the city of Bombay and also at 111, Radhabazar Street, Calcutta and residing at 23, Ballygunge Circular Road in this city. The Defendants were firstly George Reinhart, Werner Reinhart, Oskar Reinhart, and Peter Reinhart, a partnership firm constituted according to the relative laws of the Swiss Republic trading under the name and style of Volkart Brothers and carrying on business in the said firm name at Volkart Buildings, 19, Ballard Estate, Bombay and amongst other places, at 11, Clive Street in the city of Calcutta as Agents, secondly Radha Kanta Doss and Sons, Limited, a company limited by shares and incorporated in India under the Indian Companies Act (VII of 1913) having their registered offices and carrying on business at amongst other places 210 and 211, Old China Bazar Street in Calcutta as dealers.

2. In the suit the Plaintiff firm as the grantee of two Indian Letters Patent in respect of improvements in and relating to hurricane lamps namely, Indian Letters Patent No. 19006 as of the 13th of June, 1932, and No. 19157 as of the 29th of August, 1932, (through Hans George Fischer, one of its constituted attorneys in this country) claimed a perpetual injunction and other appropriate reliefs in respect of alleged infringements of those Patents. The suit was instituted on the 20th of December, 1935.

3. Appeal No. 66 of 1937 arises out of proceedings which were intituled---

4. In the matter of Letters Patent granted to Hermann Nier numbered 19006 of 1932,.. And In the matter of the Indian Patents and Designs Act, II of 1911 And In the matter of an application by Harold Augustus De Penning under sec. 26 of the said Act.

5. These proceedings were taken by a concern called the R. E. Dietz Company (Inc) of New York in the United States of America against the Hermann Nier firm above-mentioned for the purpose of obtaining an order that the Letters Patent No. 19006 of 1932 granted to that firm should be revoked. It will be convenient to refer to the two sets of proceedings respectively as the " infringement suit" and " the revocation proceedings." Before dealing with the actual proceedings it is perhaps useful to re-call the antecedent history of the relations between the parties.

6. For a number of years before the Great War both the Hermann Nier firm and the R. E. Dietz Company (Inc) carried on business as manufacturers and sellers of hurricane lamps. The R. E Dietz Company sold and still sell their lamps designated by specific names for each variety or type whereas the Hermann Nier firm used the general trade name of "Feurhand" for all their lamps, but sold the different varieties of their lamps identified by numbers. In or about the year 1909 the R. E. Dietz Company (Inc) put on the market a lamp which they called "the Wizard " and that was followed on the part of the Hermann Nier firm by a lamp known as Feurhand No. 260. In the year 1914 the R. E. Dietz Company (Inc) produced a lamp which they