<p class="MsoNormal" style="line-height: normal; margin: 0in 0in 10pt;"><span style="mso-bidi-font-family: 'Times New Roman';" lang="EN-GB"><span style="font-size: small;"><span style="font-family: Times New Roman;">In the German concentration camps, the inmates invariably had to get up and start work even before amud hashachar. In some cases, with great mesiras nefesh, they succeeded in smuggling in a pair of tefillin. The question was whether one could put on tefillin before amud hashachar and furthermore, whether one could say a berachah over the tefillin? This question was answered by Rav Efraim Oshri, who was Rav of the Kovno Ghetto in Lithuania, (Divrei Efraim, responsum 2) who ruled that under such circumstances one could put on tefillin and also say the berachah over them. He wrote that the concern of Chazal that one might fall asleep with the tefillin on was not relevant here, since any person doing so would endanger his life.</span></span></span></p>

<p class="MsoNormal" style="line-height: normal; margin: 0in 0in 10pt;"><span style="mso-bidi-font-family: 'Times New Roman';" lang="EN-GB"><span style="font-size: small;"><span style="font-family: Times New Roman;">It was nearly 50 years ago that the British branch of the Association of Orthodox Jewish Scientists performed practical experiments to determine the time of yakir relative to sunrise. A paper was written up on this and I think it appeared in the journal &ldquo;Intercom&rdquo; brought out by the American branch of this Association. The results of their experiments showed that the time for yakir depended on a number of factors, one which I remember was whether the person to be identified was facing east or west.</span></span></span></p>