I have just finished reading an article, Sensitometry Pioneers, by Ron Callender, published in Nov 2012 volume of the Royal Photographic Society Journal. I was astonished to learn that almost until a few days before Hurter's death in 1898 they had been constantly attacked for their crucial discoveries, and how those quarrels brought Hurter much grief. As many of you may know, the HD, or characteristic curve is named after them. Vero Charles Driffield and Ferdinand Hurter formalised the relationship between: the emulsion, light exposure, the action of the developer, and the resulting negative densities. This started the discipline of sensitometry, and thanks to them, photography made its first stab at defining sensitivity of photographic materials. Whenever I read Stephen Benskin's, Ralph Lambrecht's, Bill Burke's, or Michael 1974's patient posts, and the many books about the Zone System, I always think back to Hurter and Driffield. Pardon me for summarising what I read in that RPS Journal, but I wanted to share it with you, as it is not available online. In 1888 Hurter and Driffield pioneered actinograph speeding, which they improved four years later, as the H & D Speed System. That's where the trouble started, according to the correspondence unearthed by the article's author. Many dry plate manufacturers dreaded the idea of having a speed of their products measured by an independent, scientific method. Even worse, the authorities at the time, such as Captain William de Wiveleslie Abney, and other writers for the Photography magazine, actively attacked our pioneers through their writings, lectures, and even by supplying their own, mathematically shaky contradictions. They forced key Hurter and Driffield findings even off the very frst inaugural RPS memorial lecture, after their death! Apparently, all of this sat under a dust cover in a pile of letters at RPS headquarters, until it was discovered, by Callender, six years ago, after RPS moved to Bath. How sad, but also how nice that 130 years later the truth has prevailed. PS. Apparently, there is a booklet on the subject, called "Mr Driffield and Dr Hurter. Their lives & times in pictures" by Callender". If you search the web you can find references to it, I'll be getting a copy.