I recently came across this little-known method which, considering the year of it's invention - 1860 - is, I think, a very ingenious technique. Harbison duly filed a Patent (US 26,431) for this technique and even wrote a book 'An Improved System of Propagating the Honey Bee' about it - but the essence of his method can very easily be described in a few short sentences, and with just one diagram.
A queenless colony is created, into which a comb of brood from a desirable queen will be inserted within which eggs and young larvae have been identified.
A section of that comb containing them is then removed. This section being typically around 3 inches long and - this being the only slightly tricky bit - as deep as the comb is thick. So we're looking at around 7/8" or 22mm deep. This section is then to be re-inserted having been rotated through 90 degrees, such that the desirable cells on the underside are pointing directly downwards - labelled 'A' in the following diagram:
BUT - before inserting that section with it's new orientation, a further section of comb is removed below the first - shown as 'B' in the above diagram, ensuring that shoulders remain to support the now vertical section inserted above it. Queen-cells will then be drawn within that space.
That's all there is to it - perhaps this could be thought of as a mini-Hopkins technique ?
All other aspects of the method - queenlessness, stocking with nurse bees, the need for stores & pollen combs etc. - are exactly the same as with any queenless cell-raising method.
By posting this I'm not suggesting that the Harbison Method is better (or worse) that those of Alley or Hopkins - but considering the date, 1860, I reckon it's quite an ingenious technique.