270 GEORGE HOGGAN OS A 



steady, as well as the article to be cut, with the fingers of my felt 

 hand, while I used the saw with my right, I considered it advisable 

 to screw the frame upon a portable table or block of wood, so that 

 I now only required to hold the article to be cut with the fingers 

 of my left hand, while I cut with my right. My next step was to 

 contrive an arrangement which would fix the article to be cut on 

 the table ; this completely relieved the fingers of my left hand, but 

 it had stil] the inconvenience of requiring to be unfixed and care- 

 fully refixed in the plane of the preceding cut at every section, in 

 order that it might be of equal thickness throughout. I there- 

 fore contrived to fix it on a metal table, moving at right angles to 

 the track of the saw, and in order to obviate any awkward jerking 

 or unequal movement, I gave it motion by a screw, which enabled 

 me to move it correctly to the g-J^o^h part of an inch, and to tell the 

 thickness of the section at the same time. 



I next experienced inconvenience from the saw cutting into the 

 brass frame, so that it was necessary to form a facing of hardened 

 steel, and as I found that unless great care was used the saw was 

 apt to cut awry, I placed a similar steel facing as a guide on the 

 outer side of the saw, which now moved in a thin slit of hardened 

 steel, from which it could not deviate. To make the path of the 

 saw quite correct, I filed out from the u|)per part of the machine 

 as much metal as was equal to half the thickness of the saw frame, 

 so that the centre lines of both saw and saw frame moved in the 

 same perpendicular plane ; and to complete matters, I added guides 

 for the outer side of the saw frame itself, so that sections of hard 

 materials could now be made without the exercise of any skill 

 whatever. 



From this history of its construction you will be able to under- 

 stand the general design of the machine, and I may, therefore, sum 

 up its description in a few words. 



In plate xiii., fig. 1, is a side view of my section machine as 

 arranged for cutting sections of hard substances, fig. 2 being an 

 end view of the same, and shewing the saw in position. Figs. 3, 

 4, and 5 shew the machine as arranged for cutting sections of soft 

 substances, fig. 3 being a longitudinal vertical section, fig. 4 a view 

 of the opposite end of the machine to that shewn in fig. 2, and 

 fig. 5 a sectional plan. 



It will be seen that the machine consists essentially of a metal 

 table (a) moved steadily backwards aud forwards by a graduated 



