Eruvin 152

הני מילי בעיגולא אבל בריבועא בעינן טפי

- This<span class="x" onmousemove="('comment',' That a figure with a perimeter of twelve handbreadths has a diameter of four handbreadths approx.');">¹</span> applies only to a circle, but where a square<span class="x" onmousemove="('comment',' Of given dimension, as in this case one of four handbreadths by four.');">²</span> is to be inscribed within it a greater circumference is required.<span class="x" onmousemove="('comment',' As the window under discussion must be four handbreadths square the diameter of the circle in which such a square can be inscribed must have, as laid down by R. Johanan, a minimum circumference of twenty-four hand breadths.');">³</span>

מכדי כמה מרובע יתר על העגול רביע בשיתסר סגיא

But observe: By how much does the perimeter of a square exceed that of a circle? By a quarter approximately; should not then a circumference of sixteen handbreadths<span class="x" onmousemove="('comment',' Since sixteen exceeds twelve by a quarter of the former figure.');">⁴</span> suffice?<span class="x" onmousemove="('comment',' For the window under discussion.');">⁵</span>

ה"מ עיגולא דנפיק מגו ריבועא אבל ריבועא דנפיק מגו עיגולא בעינן טפי מ"ט משום מורשא דקרנתא

- This<span class="x" onmousemove="('comment',' That the perimeter of a square exceeds the circumference of a circle by one quarter.');">⁶</span> applies only to a circle that is inscribed within<span class="x" onmousemove="('comment',' Lit., 'that goes out from'.');">⁷</span> the square, but where a square is to be inscribed within a circle it is necessar [for the circumference of the latter] to be much bigger.<span class="x" onmousemove="('comment',' Than three quarters of the given square. Hence R. Johanan's requirement that the circumference of the window must be no less than twenty-four handbreadths.');">⁸</span>

מכדי כל אמתא בריבוע אמתא ותרי חומשי באלכסונא בשיבסר נכי חומשא סגיא

What is the reason? In order [to allow<span class="x" onmousemove="('comment',' Within the circle.');">⁹</span> space for] the projections of the corners.<span class="x" onmousemove="('comment',' Of the square. A circular window with a circumference that is less than twenty-four handbreadths would not contain the area that is required.');">¹⁰</span>

רבי יוחנן אמר כי דייני דקיסרי ואמרי לה כרבנן דקיסרי דאמרי עיגולא מגו ריבועא ריבעא ריבועא מגו עיגולא פלגא:

Consider, however, this: Every cubit in [the side of] a square [corresponds to], one and two fifths cubits in its diagonal; [should not then<span class="x" onmousemove="('comment',' Since the diameter of the circle forms the diagonal of the inscribed square.');">¹¹</span> a circumference] of sixteen and four fifths handbreadths<span class="x" onmousemove="('comment',' Which has a diameter of (16 4/5) /3 = 84/ (3 X 5) = 28/5 handbreadths approximately and in which a square each side of which is equal to (5/7 of its diagonal or 28/5 X 5/7 =) four handbreadths, may be inscribed.');">¹²</span> suffice?<span class="x" onmousemove="('comment',' Why then did R. Johanan require a circumference of twenty-four handbreadths?');">¹³</span>

פחות מד' על ד' וכו': אמר רב נחמן לא שנו אלא חלון שבין ב' חצירות אבל חלון שבין ב' בתים אפילו למעלה מעשרה נמי אם רצו לערב מערבין אחד מ"ט ביתא כמאן דמלי דמי

- R'Johanan holds the same view as the judges of Caesarea or, as others say, as that of the Rabbis of Caesarea who maintain [that the area of] a circle that is inscribed within a square Is [le than the latter by] a quarter<span class="x" onmousemove="('comment',' Of that square.');">¹⁴</span> [while that of] the square that is inscribed within that circle<span class="x" onmousemove="('comment',' That was inscribed in the other square.');">¹⁵</span> [is less than the outer square by] a half.<span class="x" onmousemove="('comment',' Cf. Rashi, Tosaf., R. Han. and Rashal one or other of whom the interpretation here partly follows. While the rule laid down in Caesarea seems to bear on the area of the circle and the squares, R. Johanan applied it also to the circumference of the circle and thus required a much bigger circumference than is actually necessary for an inscribed square of four handbreadths by four.');">¹⁶</span>

איתיביה רבא לרב נחמן אחד לי חלון שבין ב' חצירות ואחד לי חלון שבין ב' בתים ואחד לי חלון שבין ב' עליות ואחד לי חלון שבין ב' גגין ואחד לי חלון שבין ב' חדרים כולן ד' על ד' בתוך עשרה

IF THE SIZE OF THE WINDOW WAS LESS THAN FOUR HANDBREADTHS BY FOUR etc. R'Nahman explained: This<span class="x" onmousemove="('comment',' That the window must not be higher than TEN HANDBREADTHS from the ground.');">¹⁷</span> was learnt only in respect of a window between two courtyards but in the case of a window between two houses, even though It was higher than ten handbreadths from the ground, the residents may, if they wish, prepare one 'erub jointly. What is the reason? - A house is regarded as filled.<span class="x" onmousemove="('comment',' The window is consequently within the prescribed ten handbreadths.');">¹⁸</span>

תרגומא אחצירות והא אחד לי קתני תרגומא אד' על ד'

Raba raised an objection against R'Nahman: A window, irrespective of whether<span class="x" onmousemove="('comment',' Lit., 'one to me'.');">¹⁹</span> it was between two courtyards, between two houses, between two upper rooms, between two roofs,<span class="x" onmousemove="('comment',' According to the Rabbis who ruled that as the residents are divided in their domains below so are they divided on their roofs above and, consequently, no movement of objects from one person's roof to that of another is permitted unless a proper 'erub is prepared.');">²⁰</span> or between two rooms, must be of the size of<span class="x" onmousemove="('comment',' Lit., 'all of them'.');">²¹</span>

בעא מיניה ר' אבא מרב נחמן לול הפתוח מן בית לעלייה צריך סולם קבוע להתירו או אין צריך סולם קבוע להתירו

four handbreadths by four within ten handbreadths from the ground? - The interpretation is [that the limitation<span class="x" onmousemove="('comment',' 'Within ten handbreadths'.');">²²</span> applies] to the courtyards.<span class="x" onmousemove="('comment',' Not to the houses.');">²³</span> But was it not stated: 'irrespective of whether'?<span class="x" onmousemove="('comment',' Which implies that houses are subject to the same restrictions as the courtyards mentioned in the same context.');">²⁴</span>

כי אמרינן ביתא כמאן דמלי דמי הני מילי מן הצד אבל באמצע לא או דילמא לא שנא

- The interpretation is that this refers to the prescribed four handbreadths by four'. R'Abba<span class="x" onmousemove="('comment',' MS.M. 'Raba'.');">²⁵</span> enquired of R'Nahman: If an aperture<span class="x" onmousemove="('comment',' In the roof of a lower room which is the floor of the upper one.');">²⁶</span>

אמר ליה אינו צריך סבור מינה סולם קבוע הוא דאינו צריך הא סולם עראי צריך איתמר אמר רב יוסף בר מניומי אמר רב נחמן אחד סולם קבוע ואחד סולם עראי אינו צריך:

led from a room to an upper room,<span class="x" onmousemove="('comment',' Jast., 'a small room opening (leading) from the ground floor to the upper room', the two rooms having been occupied by two residents respectively.');">²⁷</span> is a permanent ladder<span class="x" onmousemove="('comment',' Leading from the lower to the upper room through the aperture.');">²⁸</span> necessary for the purpose of allowing the movement of objects<span class="x" onmousemove="('comment',' Between the two rooms.');">²⁹</span>

<big><strong>מתני׳</strong></big> כותל שבין ב' חצירות גבוה עשרה ורוחב ארבעה מערבין שנים ואין מערבין אחד

or not? Do we apply the principle, that 'a house is regarded as filled' only when the aperture<span class="x" onmousemove="('comment',' As in the case of the window spoken of by R. Nahman.');">³⁰</span> is at the side but not when it is in the middle<span class="x" onmousemove="('comment',' Hence no 'erub is valid unless a ladder (cf. supra 59b) joined the lower and the upper rooms.');">³¹</span>

היו בראשו פירות אלו עולין מכאן ואוכלין ואלו עולין מכאן ואוכלין ובלבד שלא יורידו למטן

or is it possible that there is no difference? - The other replied: It is not necessary. He<span class="x" onmousemove="('comment',' R. Abba.');">³²</span> understood him<span class="x" onmousemove="('comment',' R. Nahman.');">³³</span>

נפרצה הכותל עד עשר אמות מערבין שנים ואם רצו מערבין אחד מפני שהוא כפתח יותר מכאן מערבין אחד ואין מערבין שנים:

to mean that only a permanent ladder is not necessary but that a temporary one is necessary. It was, however, stated: R'Joseph<span class="x" onmousemove="('comment',' Var. lec., 'Rab Judah in the name of R. Joseph' (Asheri) .');">³⁴</span> B'Minyomi citing R'Nahman laid down: Neither a permanent, nor a temporary ladder is necessary.

<big><strong>גמ׳</strong></big> אין בו ארבעה מאי אמר רב אויר שתי רשויות שולטת בו לא יזיז בו אפילו מלא נימא

<big><b>MISHNAH: </b></big>IF A WAIL BETWEEN TWO COURTYARDS WAS TEN HANDBREADTHS HIGH AND FOUR HANDBREADTHS THICK, TWO 'ERUBS MAY BE PREPARED<span class="x" onmousemove="('comment',' Separate ones for each courtyard.');">³⁵</span> BUT NOT ONE.<span class="x" onmousemove="('comment',' Sc. the two courtyards are not allowed to prepare a joint 'erub on account of the wall that intervened between then,. The prescribed thickness of four handbreadths, which has no bearing on this restriction since it applies to all walls whatever their thickness, was mentioned on account of the ruling that follows which is applicable only where the thickness of the wall was no less than four handbreadths. A lesser thickness does not constitute a separate domain.');">³⁶</span> IF THERE WAS FRUIT ON THE TOP OF IT,<span class="x" onmousemove="('comment',' The wall of the prescribed thickness (cf. prev. n.) .');">³⁷</span> THE TENANTS ON EITHER SIDE MAY CLIMB UP AND EAT THEM PROVIDED<span class="x" onmousemove="('comment',' Since it is forbidden to carry from one domain into another (cf. prev. two notes) .');">³⁸</span> THEY DO NOT CARRY THEM DOWN. IF A BREACH TO THE EXTENT OF TEN CUBITS WAS MADE IN THE WALL, THE TENANTS MAY PREPARE TWO 'ERUBS<span class="x" onmousemove="('comment',' Separate ones for each courtyard.');">³⁵</span> OR, IF THEY PREFER, ONLY ONE,<span class="x" onmousemove="('comment',' Jointly.');">³⁹</span> BECAUSE IT<span class="x" onmousemove="('comment',' A gap that is not bigger than ten cubits.');">⁴⁰</span> IS LIKE A DOORWAY. IF THE BREACH WAS BIGGER, ONLY ONE 'ERUB AND NOT TWO MAY BE PREPARED.<span class="x" onmousemove="('comment',' A gap so great converts the two courtyards into one; and the tenants, like those of the same courtyard, may not break up into two parties for 'erub. If they do they impose restrictions of movement upon each other.');">⁴¹</span> <big><b>GEMARA: </b></big>What is the ruling where it<span class="x" onmousemove="('comment',' The WALL.');">⁴²</span> was not FOUR HANDBREADTHS wide? - Rab replied: The air of two domains<span class="x" onmousemove="('comment',' That of the two courtyards between which it is situated.');">⁴³</span> prevails upon it and<span class="x" onmousemove="('comment',' Since it constitutes no independent domain and every fraction of its space is dominated (cf. prev. n.) by two domains.');">⁴⁴</span> no object on it may be moved even as far as a hair's breadth.