Mr. Henrick J. Hjorth had his Hjorth Lathe & Tool Company works at Woburn, Massachusetts in the USA (with the registered office at 27 School Street, Boston) and produced a range of what were known, in their day, as "Bench Lathes". However, today we have to add the word "Precision" to that description, if we are to understand the meaning of the phrase as understood in the late part of the nineteenth and early part of the twentieth centuries.
Pictured above, the screwcutting version of the lathe though based was on a 1911 patent was still available in much the same form in early 1930s. The capacity was 18" between centres and the swing 83/4"; the bed was 36" long and the machine weighed, with basic equipment, 143 lbs.
Spindle speeds depended upon the precise countershaft specified but were normally arranged to be 1000 r.p.m. on top speed and 500 rpm on bottom. While not shown on the lathe above, a backgear assembly was offered to reduce the speeds sufficiently for safe screwcutting which, on the Hjorth was transmitted to the top slide through a universal-joined shaft - a not uncommon method on early precision bench lathes. As a small aid to user-convenience, the mounting plates beneath the lathe feet were slotted, to allow a modicum of adjustment for belt tensioning. The compound slide rest, with a 51/2" top movement and a 41/2" cross movement, was topped by an eccentric toolpost very similar to that found on Rivett lathes.
So far, three headstock spindle nose fittings have been discovered: one taking a 4NS collet; another what might have been a 5NS collet, a fitting the same diameter as the common 5C but longer at 4.75" together with a different angle on the end and one ground to accept Hendey No 2 collets and equipped with the correct Hjorth-manufactures drawbar.
Both the spindle, with a 3/4" through bore, and the tailstock were fitted with a Brown and Sharpe No. 6 taper, 21/2" long. One of the optional tailstocks was very unusual in being fitted with a combination screw and lever-feed actions; the screw feed had a maximum travel of 23/4" and the lever feed 41/4".
One odd but most useful feature on the Hjorth was the use of separate mounting pads under each bed foot. These were fitted with screw adjusters, mounted at the rear, that allowed the lathe to be moved forwards slightly to compensate for belt stretch.
As was usual with this class of lathe, a host of other special accessories was available including a remarkable bed-mounted combination vertical milling, gear-cutting and dividing attachment; some examples of these accessories can be seen on the accompanying pages. Unfortunately, as with most makes of precision bench lathe, Hjorth accessories are hard to find - few having been sold in comparison with the number of lathes manufactured.
Other makers of similar lathes in the USA included: Levin, Bottum, American Watch Tool Company, Bausch & Lomb, B.C.Ames, Cataract, Crystal Lakes, Derbyshire, Elgin, Hardinge, Hjorth, W.H.Nichols, Potter, Pratt & Whitney, Remington, Rivett, Sloan & Chace, U.N.D., Van Norman, Wade, Waltham Machine Works, and (though now very rare) , Frederick Pearce, Ballou & Whitcombe, Sawyer Watch Tool Co., Engineering Appliances, Fenn-Sadler, and the "Cosa Corporation of New York".
A list of manufactures of similar lathes can be found here..