M. TECHNOLOGY. 521 



ering the cost of its treatment. It is, of course, not an easy- 

 matter to utilize this solution of suint on a small scale ; but 

 wherever the work is carried on by the wholesale, as it is in 

 connection with all great manufacturing establishments, it 

 will undoubtedly become a regular part of the process of 

 manufacture. 9 C, January 8, February 18, 1872. 



CLEANING SEWING-MACHINES. 



A writer in the Leipsic Polytechnic Journal has an extended 

 article upon the proper method of cleaning sewing-machines 

 that require such treatment, and begins by cautioning the 

 owners against carelessly submitting them to the manipula- 

 tion of even professional machinists for this purpose. The 

 parts of the sewing-machine are so carefully adjusted to each 

 other that any abrasion of the bearings will necessarily in- 

 volve irregularity of motion, which will increase in time, un- 

 til the whole machine becomes worthless. For this reason it 

 is desirable to oil the different parts of the machine without 

 taking them apart, even although this should be superin- 

 tended by a careful artificer. According to the writer, the 

 principal cause of injury to the machine consists in the ac- 

 cumulation of dust from the fabrics upon which it is used, 

 this being so minute as to be inappreciable by the naked eye, 

 but nevertheless accumulating and becoming fixed in the 

 working-gear, and attracting the dust of the atmosphere. 

 The best substance for the purpose of cleaning the machine 

 is said to be fat from sheeps' feet, which is to be placed in 

 tolerable abundance upon the bearing surfaces of the ma- 

 chine to be oiled, which is then to be set in rapid motion. 

 This fat acts on the bearings, and when melted by the heat of 

 friction is driven out again, mixed with the dirt and blackish 

 matter from the machine. This is to be wiped off with a 

 soft cloth, and a quantity of fat again applied, to be again 

 treated in the same way, and this operation is to be continued 

 until the fat, as it comes from the joint, is clear and free from 

 dirt, after which the machine may be considered as entirely 

 clean. 



When the machine has become rusty in any of its bearings, 

 this is to be removed very carefully by fine emery paper, al- 

 though, if the trouble is not very serious, the application of 

 fat as described will probably answer every purpose, and this 



