Reference for Shabbat 195:4
סוף סוף סומכא דקרש כמה הוי אמתא כמה הוה מותיב ארבעה פשא לה אמתא כי שדי לה מר ביני וביני כלבוד דמי הניחא למ"ד קרשים מלמטן עוביין אמה מלמעלן כלין והולכין עד כאצבע שפיר אלא למ"ד כשם שמלמטן עוביין אמה כך מלמעלה עוביין אמה מאי איכא למימר
— Consider: what was the length of the waggons? Five cubits. What was the breadth of the board? A cubit and a half. Then how many [rows] could be placed: three: thus leaving half a cubit, and when you divide it among them [the spaces] they are as joined!<span class="x" onmousemove="('comment',' For there was only a quarter cubit one and a half handbreadths between the rows of boards, whereas a space less then three cubits is disregarded (v. supra 97a). ');"><sup>7</sup></span> — Do you think that the boards lay on their width? they were laid on their thickness. Yet even so, what was the thickness of the board? One cubit. How many [rows] were [then] laid? Four, thus leaving a cubit, and when you divide it among them [the spaces] they are as joined!<span class="x" onmousemove="('comment',' For there are three spaces which give two handbreadths for each. ');"><sup>8</sup></span>