D O C . 2 8 0 J A N U A R Y 1 9 2 0 2 3 1 the campaign of lies which has lasted for five years—in all countries—you will not judge these poor islanders too harshly. Yours very truly, E.B. Ludlam. 280. From Edouard Guillaume[1] Bern, 12 Dittlinger Way, 25 January 1920 Dear Einstein, I do not need to tell you what pleasure the experimental confirmation of your fine theory gave me.[2] That I value your theory very highly already arises from the fact that I have been working intensely on it for two years.[3] Now, however, I have arrived at results that are so important for the development of the theory that I take it as my duty to inform you of them without delay.[4] A detailed paper will soon appear in the Archives. For, my studies of space and time led me to the conclusion that a basic error re- garding time is hidden in the theory. First, I mention the following in advance: On a clock we can read off the time either from the little hand or the big one, by using the minute gauge alone. Whereas the big hand moves through 60 scale divi- sions, the little one moves through just 5. Hence we have as a transformation equa- tion: Δt and are simply different measures of the same time span Δt refers to the big hand, to the little one. If we introduce the times for each revolution (period), we obtain the equation . It is important to note that in the latter equation the index occurs on the other side from that in the former. While it would be completely wrong to use the same unit of time (“minutes,” for ex.) in the first equation, in the 2nd equation one must nec- essarily measure and with the same time unit, in hours, for ex. (1 hr. for the big hand, 12 hrs. for the little one). This said, let us examine the Lorentz equation:[5] and let us set . We obtain: (1) . Δt 12Δt′ = Δt′ Δt′ Θ′ 12Θ = Θ Θ′ coΔt β( = coΔt′ αΔx′), + Δx′ 0 = Δt βΔt′ Δt′ 1 α2 – ------------------ - = =